diff --git a/asterix-app/data/events/tiny/event.adm b/asterix-app/data/events/tiny/event.adm
index 21fd7e7..5e9d4b3 100644
--- a/asterix-app/data/events/tiny/event.adm
+++ b/asterix-app/data/events/tiny/event.adm
@@ -5,8 +5,8 @@
     "sponsoring_sigs": [ { "sig_id": 14, "chapter_name": "San Clemente" }, 
                          { "sig_id": 14, "chapter_name": "Laguna Beach" } ],
     "interest_keywords": {{ "art", "landscape", "nature", "vernissage" }},
-    "start_time": datetime( "2011-02-23T18:00:00:000-08:00" ),
-    "end_time": datetime( "2011-02-23T21:00:00:000-08:00" ) 
+    "start_time": datetime( "2011-02-23T18:00:00.000-08:00" ),
+    "end_time": datetime( "2011-02-23T21:00:00.000-08:00" ) 
   }
   { 
     "event_id": 941, 
@@ -16,8 +16,8 @@
     "sponsoring_sigs": [ { "sig_id": 31, "chapter_name": "Huntington Beach" } ],
     "interest_keywords": {{ "scuba", "diving", "aquatics" }},
     "price": 40.00,
-    "start_time": datetime( "2010-10-16T09:00:00:000-08:00" ),
-    "end_time": datetime( "2010-10-16T12:00:00:000-08:00" )
+    "start_time": datetime( "2010-10-16T09:00:00.000-08:00" ),
+    "end_time": datetime( "2010-10-16T12:00:00.000-08:00" )
   }
   { 
     "event_id": 1042, 
@@ -26,7 +26,7 @@
     "sponsoring_sigs": [ { "sig_id": 14, "chapter_name": "Laguna Beach" } ],
     "interest_keywords": {{ "architecture", "photography" }},
     "price": 10.00,
-    "start_time": datetime( "2011-02-23T17:00:00:000-08:00" ),
-    "end_time": datetime( "2011-02-23T19:00:00:000-08:00" ) 
+    "start_time": datetime( "2011-02-23T17:00:00.000-08:00" ),
+    "end_time": datetime( "2011-02-23T19:00:00.000-08:00" ) 
   } 
   
\ No newline at end of file
diff --git a/asterix-app/data/nontagged/tempData.json b/asterix-app/data/nontagged/tempData.json
index 1fef3ab..dfcfa1e 100644
--- a/asterix-app/data/nontagged/tempData.json
+++ b/asterix-app/data/nontagged/tempData.json
@@ -1,2 +1,2 @@
-{ "id": 10, "date": date("2011-01-27"), "time": time("12:20:30"), "datetime": datetime("1951-12-27T12:20:30"),  "duration": duration("D30Y10M15DT10H30M50S"), "date2": date("2011-01-27-05:00"), "time2": time("12:20:30:999-05:00"), "datetime2": datetime("1951-12-27T12:20:30:250-08:45"),  "duration2": duration("D10M15DT10H50S"), "date3": date("-2011-01-27-05:00"), "time3": time("12:20:30:999Z"), "datetime3": datetime("-1951-12-27T12:20:30:250-08:15"),  "duration3": duration("-DT50S"), "date4": date("-2011-01-27Z"), "time4": time("12:20:30Z"), "datetime4": datetime("-1951-12-27T12:20:30:250Z"), "duration4": duration("-D10M"), "date5": date("2011-01-27"), "time5": time("12:20:30"), "datetime5": datetime("1951-12-27T12:20:30"),  "duration5": duration("D30Y10M15DT10H30M50S") }
+{ "id": 10, "date": date("2011-01-27"), "time": time("12:20:30"), "datetime": datetime("1951-12-27T12:20:30"),  "duration": duration("D30Y10M15DT10H30M50S"), "date2": date("2011-01-27-05:00"), "time2": time("12:20:30:999-05:00"), "datetime2": datetime("1951-12-27T12:20:30.250-08:45"),  "duration2": duration("D10M15DT10H50S"), "date3": date("-2011-01-27-05:00"), "time3": time("12:20:30:999Z"), "datetime3": datetime("-1951-12-27T12:20:30.250-08:15"),  "duration3": duration("-DT50S"), "date4": date("-2011-01-27Z"), "time4": time("12:20:30Z"), "datetime4": datetime("-1951-12-27T12:20:30.250Z"), "duration4": duration("-D10M"), "date5": date("2011-01-27"), "time5": time("12:20:30"), "datetime5": datetime("1951-12-27T12:20:30"),  "duration5": duration("D30Y10M15DT10H30M50S") }
 
diff --git a/asterix-app/src/test/resources/aqljts/results/nested_01.adm b/asterix-app/src/test/resources/aqljts/results/nested_01.adm
index 54444c7..27de5c0 100644
--- a/asterix-app/src/test/resources/aqljts/results/nested_01.adm
+++ b/asterix-app/src/test/resources/aqljts/results/nested_01.adm
@@ -30,4 +30,4 @@
 ARecordType: 
 field: t
 AbstractCollectionType: 
-ADateTime: { 2011-9-16:11:0:0:0:0:0 }
+ADateTime: { 2011-09-16T11:00:00.000Z }
diff --git a/asterix-app/src/test/resources/runtimets/queries/constructor/datetime_01.aql b/asterix-app/src/test/resources/runtimets/queries/constructor/datetime_01.aql
index 611feff..8c29dac 100644
--- a/asterix-app/src/test/resources/runtimets/queries/constructor/datetime_01.aql
+++ b/asterix-app/src/test/resources/runtimets/queries/constructor/datetime_01.aql
@@ -1,13 +1,15 @@
+drop dataverse test if exists;
+create dataverse test;
 use dataverse test;
 
 write output to nc1:"rttest/constructor_datetime_01.adm";
 
-let $c1 := datetime("2010-10-30T10:50:56:999+05:45")
-let $c2 := datetime("2010-10-30T10:30:56:250-10:00")
-let $c3 := datetime("1987-11-19T09:20:00:200")
+let $c1 := datetime("2010-10-30T10:50:56.999+05:45")
+let $c2 := datetime("2010-10-30T10:30:56.250-10:00")
+let $c3 := datetime("1987-11-19T09:20:00.200Z")
 let $c4 := datetime("1987-11-19T10:50:56Z")
-let $c5 := datetime("-1987-11-19T10:50:56:099-05:30")
-let $c6 := datetime("-0001-11-19T10:50:56:719Z")
-let $c7 := datetime("1951-12-27T12:20:15")
+let $c5 := datetime("-1987-11-19T10:50:56.099-05:30")
+let $c6 := datetime("-0001-11-19T10:50:56.719Z")
+let $c7 := datetime("1951-12-27T12:20:15Z")
 return {"datetime1": $c1, "datetime2": $c2, "datetime3": $c3, "datetime4": $c4, "datetime5": $c5, "datetime6": $c6, "datetime7": $c7}
 
diff --git a/asterix-app/src/test/resources/runtimets/results/comparison/datetime_order.adm b/asterix-app/src/test/resources/runtimets/results/comparison/datetime_order.adm
index 14f3ab1..63d22af 100644
--- a/asterix-app/src/test/resources/runtimets/results/comparison/datetime_order.adm
+++ b/asterix-app/src/test/resources/runtimets/results/comparison/datetime_order.adm
@@ -1,5 +1,5 @@
-datetime("2005-01-01T00:00:00:000+04:00")
-datetime("2012-01-01T00:00:00:000+00:00")
-datetime("2011-12-31T14:00:00:000-10:00")
-datetime("2011-12-31T13:00:00:000-11:00")
-datetime("2012-04-06T00:00:00:000+00:00")
+datetime("2004-12-31T20:00:00.000Z")
+datetime("2012-01-01T00:00:00.000Z")
+datetime("2012-01-01T00:00:00.000Z")
+datetime("2012-01-01T00:00:00.000Z")
+datetime("2012-04-06T00:00:00.000Z")
diff --git a/asterix-app/src/test/resources/runtimets/results/constructor/datetime_01.adm b/asterix-app/src/test/resources/runtimets/results/constructor/datetime_01.adm
index 30d2cdb..8f2dff0 100644
--- a/asterix-app/src/test/resources/runtimets/results/constructor/datetime_01.adm
+++ b/asterix-app/src/test/resources/runtimets/results/constructor/datetime_01.adm
@@ -1 +1 @@
-{ "datetime1": datetime("2010-10-30T10:50:56:980+05:45"), "datetime2": datetime("2010-10-30T10:30:56:240-10:00"), "datetime3": datetime("1987-11-19T09:20:00:200+00:00"), "datetime4": datetime("1987-11-19T10:50:56:000+00:00"), "datetime5": datetime("-1987-11-19T10:50:56:080-05:30"), "datetime6": datetime("-0001-11-19T10:50:56:700+00:00"), "datetime7": datetime("1951-12-27T12:20:15:000+00:00") }
+{ "datetime1": datetime("2010-10-30T05:05:56.999Z"), "datetime2": datetime("2010-10-30T20:30:56.250Z"), "datetime3": datetime("1987-11-19T09:20:00.200Z"), "datetime4": datetime("1987-11-19T10:50:56.000Z"), "datetime5": datetime("-1987-11-19T16:20:56.099Z"), "datetime6": datetime("-0001-11-19T10:50:56.719Z"), "datetime7": datetime("1951-12-27T12:20:15.000Z") }
diff --git a/asterix-app/src/test/resources/runtimets/results/scan/alltypes_01.adm b/asterix-app/src/test/resources/runtimets/results/scan/alltypes_01.adm
index 3fad2e3..206461c 100644
--- a/asterix-app/src/test/resources/runtimets/results/scan/alltypes_01.adm
+++ b/asterix-app/src/test/resources/runtimets/results/scan/alltypes_01.adm
@@ -1 +1 @@
-{ "id": 10, "name": "Nancy", "age": 32.5f, "salary": 12.0d, "married": true, "interests": {{ "reading", "writing" }}, "children": [ "Brad", "Scott" ], "address": { "number": 8389, "street": "Hill St.", "city": "Mountain View" }, "dob": date("-2011-01-27+00:00"), "time": time("12:20:30:000+00:00"), "datetime": datetime("-1951-12-27T12:20:30:000+00:00"), "duration": duration("D10Y11M12DT10H50M30S"), "location2d": point("41.0,44.0"), "location3d": point3d("44.0,13.0,41.0"), "line": line("10.1,11.1 10.2,11.2"), "polygon": polygon("1.2,1.3 2.1,2.5 3.5,3.6 4.6,4.8"), "circle": circle("10.1,11.1 10.2") }
+{ "id": 10, "name": "Nancy", "age": 32.5f, "salary": 12.0d, "married": true, "interests": {{ "reading", "writing" }}, "children": [ "Brad", "Scott" ], "address": { "number": 8389, "street": "Hill St.", "city": "Mountain View" }, "dob": date("-2011-01-27+00:00"), "time": time("12:20:30:000+00:00"), "datetime": datetime("-1951-12-27T12:20:30.000Z"), "duration": duration("D10Y11M12DT10H50M30S"), "location2d": point("41.0,44.0"), "location3d": point3d("44.0,13.0,41.0"), "line": line("10.1,11.1 10.2,11.2"), "polygon": polygon("1.2,1.3 2.1,2.5 3.5,3.6 4.6,4.8"), "circle": circle("10.1,11.1 10.2") }
diff --git a/asterix-app/src/test/resources/runtimets/results/scan/temp_types_01.adm b/asterix-app/src/test/resources/runtimets/results/scan/temp_types_01.adm
index 013a0cb..05a81df 100644
--- a/asterix-app/src/test/resources/runtimets/results/scan/temp_types_01.adm
+++ b/asterix-app/src/test/resources/runtimets/results/scan/temp_types_01.adm
@@ -1 +1 @@
-{ "id": 10, "date": date("2011-01-27+00:00"), "time": time("12:20:30:000+00:00"), "datetime": datetime("1951-12-27T12:20:30:000+00:00"), "duration": duration("D30Y10M15DT10H30M50S"), "date2": date("2011-01-27-05:00"), "time2": time("12:20:30:980-05:00"), "datetime2": datetime("1951-12-27T12:20:30:240-08:45"), "duration2": duration("D0Y10M15DT10H0M50S"), "date3": date("-2011-01-27-05:00"), "time3": time("12:20:30:980+00:00"), "datetime3": datetime("-1951-12-27T12:20:30:240-08:15"), "duration3": duration("-D0Y0M0DT0H0M50S"), "date4": date("-2011-01-27+00:00"), "time4": time("12:20:30:000+00:00"), "datetime4": datetime("-1951-12-27T12:20:30:240+00:00"), "duration4": duration("-D0Y10M0DT0H0M0S"), "date5": date("2011-01-27+00:00"), "time5": time("12:20:30:000+00:00"), "datetime5": datetime("1951-12-27T12:20:30:000+00:00"), "duration5": duration("D30Y10M15DT10H30M50S") }
\ No newline at end of file
+{ "id": 10, "date": date("2011-01-27+00:00"), "time": time("12:20:30:000+00:00"), "datetime": datetime("1951-12-27T12:20:30.000Z"), "duration": duration("D30Y10M15DT10H30M50S"), "date2": date("2011-01-27-05:00"), "time2": time("12:20:30:980-05:00"), "datetime2": datetime("1951-12-27T21:05:30.250Z"), "duration2": duration("D0Y10M15DT10H0M50S"), "date3": date("-2011-01-27-05:00"), "time3": time("12:20:30:980+00:00"), "datetime3": datetime("-1951-12-27T20:35:30.250Z"), "duration3": duration("-D0Y0M0DT0H0M50S"), "date4": date("-2011-01-27+00:00"), "time4": time("12:20:30:000+00:00"), "datetime4": datetime("-1951-12-27T12:20:30.250Z"), "duration4": duration("-D0Y10M0DT0H0M0S"), "date5": date("2011-01-27+00:00"), "time5": time("12:20:30:000+00:00"), "datetime5": datetime("1951-12-27T12:20:30.000Z"), "duration5": duration("D30Y10M15DT10H30M50S") }
\ No newline at end of file
diff --git a/asterix-om/src/main/java/edu/uci/ics/asterix/dataflow/data/nontagged/comparators/ADateTimeAscBinaryComparatorFactory.java b/asterix-om/src/main/java/edu/uci/ics/asterix/dataflow/data/nontagged/comparators/ADateTimeAscBinaryComparatorFactory.java
index b62c21a..2dd8785 100644
--- a/asterix-om/src/main/java/edu/uci/ics/asterix/dataflow/data/nontagged/comparators/ADateTimeAscBinaryComparatorFactory.java
+++ b/asterix-om/src/main/java/edu/uci/ics/asterix/dataflow/data/nontagged/comparators/ADateTimeAscBinaryComparatorFactory.java
@@ -1,6 +1,5 @@
 package edu.uci.ics.asterix.dataflow.data.nontagged.comparators;
 
-import edu.uci.ics.asterix.om.base.AMutableDateTime;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparator;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 
@@ -15,41 +14,27 @@
     @Override
     public IBinaryComparator createBinaryComparator() {
         return new IBinaryComparator() {
-        	
-            private AMutableDateTime dt1 = new AMutableDateTime(0, 0, 0, 0, 0, 0, 0, 0, 0);
-            private AMutableDateTime dt2 = new AMutableDateTime(0, 0, 0, 0, 0, 0, 0, 0, 0);
 
             @Override
             public int compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2) {
-                short year = (short) (((b1[s1] & 0xff) << 8) | b1[s1 + 1] & 0xff);
-                int time = ((b1[s1 + 4] & 0xff) << 24) | ((b1[s1 + 5] & 0xff) << 16) | ((b1[s1 + 6] & 0xff) << 8)
-                        | (b1[s1 + 7] & 0xff);
 
-                dt1.setValue(year >> 1, // year
-                        (year & 0x0001) * 8 + ((b1[s1 + 2] >>> 5) & 0x07), // month
-                        b1[s1 + 2] & 0x1f, // day
-                        (short) ((time) * 20 % 216000000 / 3600000), // hour
-                        (short) ((time) * 20 % 3600000 / 60000), // minutes
-                        (short) ((time) * 20 % 60000 / 1000), // seconds
-                        (short) ((time) * 20 % 1000), // milliseconds
-                        0, // microseconds
-                        b1[s1 + 3]); // timezone
+                long chrononTime1 = getLong(b1, s1);
+                long chrononTime2 = getLong(b2, s2);
 
-                year = (short) (((b2[s2] & 0xff) << 8) | b2[s2 + 1] & 0xff);
-                time = ((b2[s2 + 4] & 0xff) << 24) | ((b2[s2 + 5] & 0xff) << 16) | ((b2[s2 + 6] & 0xff) << 8)
-                        | (b2[s2 + 7] & 0xff);
+                if (chrononTime1 > chrononTime2) {
+                    return 1;
+                } else if (chrononTime1 < chrononTime2) {
+                    return -1;
+                } else {
+                    return 0;
+                }
+            }
 
-                dt2.setValue(year >> 1, // year
-                        (year & 0x0001) * 8 + ((b2[s2 + 2] >>> 5) & 0x07), // month
-                        b2[s2 + 2] & 0x1f, // day
-                        (short) ((time) * 20 % 216000000 / 3600000), // hour
-                        (short) ((time) * 20 % 3600000 / 60000), // minutes
-                        (short) ((time) * 20 % 60000 / 1000), // seconds
-                        (short) ((time) * 20 % 1000), // milliseconds
-                        0, // microseconds
-                        b2[s2 + 3]); // timezone
-
-                return dt1.compare(dt2);
+            private long getLong(byte[] bytes, int start) {
+                return (((long) (bytes[start] & 0xff)) << 56) + (((long) (bytes[start + 1] & 0xff)) << 48)
+                        + (((long) (bytes[start + 2] & 0xff)) << 40) + (((long) (bytes[start + 3] & 0xff)) << 32)
+                        + (((long) (bytes[start + 4] & 0xff)) << 24) + (((long) (bytes[start + 5] & 0xff)) << 16)
+                        + (((long) (bytes[start + 6] & 0xff)) << 8) + (((long) (bytes[start + 7] & 0xff)) << 0);
             }
 
         };
diff --git a/asterix-om/src/main/java/edu/uci/ics/asterix/dataflow/data/nontagged/printers/ADateTimePrinter.java b/asterix-om/src/main/java/edu/uci/ics/asterix/dataflow/data/nontagged/printers/ADateTimePrinter.java
index e3999f1..5fd6905 100644
--- a/asterix-om/src/main/java/edu/uci/ics/asterix/dataflow/data/nontagged/printers/ADateTimePrinter.java
+++ b/asterix-om/src/main/java/edu/uci/ics/asterix/dataflow/data/nontagged/printers/ADateTimePrinter.java
@@ -1,13 +1,11 @@
 package edu.uci.ics.asterix.dataflow.data.nontagged.printers;
 
-import java.io.IOException;
 import java.io.PrintStream;
 
-import edu.uci.ics.asterix.dataflow.data.nontagged.serde.AInt16SerializerDeserializer;
-import edu.uci.ics.asterix.dataflow.data.nontagged.serde.AInt32SerializerDeserializer;
+import edu.uci.ics.asterix.dataflow.data.nontagged.serde.AInt64SerializerDeserializer;
+import edu.uci.ics.asterix.om.base.temporal.GregorianCalendarSystem;
 import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
 import edu.uci.ics.hyracks.algebricks.data.IPrinter;
-import edu.uci.ics.hyracks.algebricks.data.utils.WriteValueTools;
 
 public class ADateTimePrinter implements IPrinter {
 
@@ -21,49 +19,64 @@
 
     @Override
     public void print(byte[] b, int s, int l, PrintStream ps) throws AlgebricksException {
-        int year = AInt16SerializerDeserializer.getShort(b, s + 1) >> 1;
-        int month = (AInt16SerializerDeserializer.getShort(b, s + 1) & 0x0001) * 8 + ((b[s + 3] >> 5) & 0x07);
+        long chrononTime = AInt64SerializerDeserializer.getLong(b, s + 1);
 
-        int day = b[s + 3] & 0x1f;
-        byte timezone = b[s + 4];
+        GregorianCalendarSystem calendar = GregorianCalendarSystem.getInstance();
 
-        int time = AInt32SerializerDeserializer.getInt(b, s + 5);
-        // int msec = (time) * 20 % 1000;
-        // int sec = (time) * 20 % 60000 / 1000;
-        // int min = (time) * 20 % 3600000 / 60000;
-        // int hour = (time) * 20 % 216000000 / 3600000;
+        int year = calendar.getYear(chrononTime);
+        int month = calendar.getMonthOfYear(chrononTime, year);
 
         ps.print("datetime(\"");
-        if (year < 0) {
-            ps.print("-");
-        }
-        int y = Math.abs(year);
-        if (y < 1000) {
-            ps.print("0");
-        }
-        if (y < 100) {
-            ps.print("0");
-        }
-        if (y < 10) {
-            ps.print("0");
-        }
-        try {
-            WriteValueTools.writeInt(y, ps);
-            ps.print("-");
-            if (month < 10) {
-                ps.print("0");
-            }
-            WriteValueTools.writeInt(month, ps);
-            ps.print("-");
-            if (day < 10) {
-                ps.print("0");
-            }
-            WriteValueTools.writeInt(day, ps);
-            ps.print("T");
-        } catch (IOException e) {
-            throw new AlgebricksException(e);
-        }
-        ATimePrinter.printTime(time, timezone, ps);
+        ps.append(String.format(year < 0 ? "%05d" : "%04d", year)).append("-").append(String.format("%02d", month))
+                .append("-").append(String.format("%02d", calendar.getDayOfMonthYear(chrononTime, year, month)))
+                .append("T").append(String.format("%02d", calendar.getHourOfDay(chrononTime))).append(":")
+                .append(String.format("%02d", calendar.getMinOfHour(chrononTime))).append(":")
+                .append(String.format("%02d", calendar.getSecOfMin(chrononTime))).append(".")
+                .append(String.format("%03d", calendar.getMillisOfSec(chrononTime))).append("Z");
         ps.print("\")");
+        //        int year = AInt16SerializerDeserializer.getShort(b, s + 1) >> 1;
+        //        int month = (AInt16SerializerDeserializer.getShort(b, s + 1) & 0x0001) * 8 + ((b[s + 3] >> 5) & 0x07);
+        //
+        //        int day = b[s + 3] & 0x1f;
+        //        byte timezone = b[s + 4];
+        //
+        //        int time = AInt32SerializerDeserializer.getInt(b, s + 5);
+        //        // int msec = (time) * 20 % 1000;
+        //        // int sec = (time) * 20 % 60000 / 1000;
+        //        // int min = (time) * 20 % 3600000 / 60000;
+        //        // int hour = (time) * 20 % 216000000 / 3600000;
+        //
+        //        ps.print("datetime(\"");
+        //        if (year < 0) {
+        //            ps.print("-");
+        //        }
+        //        int y = Math.abs(year);
+        //        if (y < 1000) {
+        //            ps.print("0");
+        //        }
+        //        if (y < 100) {
+        //            ps.print("0");
+        //        }
+        //        if (y < 10) {
+        //            ps.print("0");
+        //        }
+        //        try {
+        //            WriteValueTools.writeInt(y, ps);
+        //            ps.print("-");
+        //            if (month < 10) {
+        //                ps.print("0");
+        //            }
+        //            WriteValueTools.writeInt(month, ps);
+        //            ps.print("-");
+        //            if (day < 10) {
+        //                ps.print("0");
+        //            }
+        //            WriteValueTools.writeInt(day, ps);
+        //            ps.print("T");
+        //        } catch (IOException e) {
+        //            throw new AlgebricksException(e);
+        //        }
+        //        ATimePrinter.printTime(time, timezone, ps);
+        //        ps.print("\")");
     }
 }
\ No newline at end of file
diff --git a/asterix-om/src/main/java/edu/uci/ics/asterix/dataflow/data/nontagged/serde/ADateTimeSerializerDeserializer.java b/asterix-om/src/main/java/edu/uci/ics/asterix/dataflow/data/nontagged/serde/ADateTimeSerializerDeserializer.java
index c22da77..75194c6 100644
--- a/asterix-om/src/main/java/edu/uci/ics/asterix/dataflow/data/nontagged/serde/ADateTimeSerializerDeserializer.java
+++ b/asterix-om/src/main/java/edu/uci/ics/asterix/dataflow/data/nontagged/serde/ADateTimeSerializerDeserializer.java
@@ -7,6 +7,7 @@
 import edu.uci.ics.asterix.formats.nontagged.AqlSerializerDeserializerProvider;
 import edu.uci.ics.asterix.om.base.ADateTime;
 import edu.uci.ics.asterix.om.base.AMutableDateTime;
+import edu.uci.ics.asterix.om.base.temporal.GregorianCalendarSystem;
 import edu.uci.ics.asterix.om.types.BuiltinType;
 import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
@@ -19,13 +20,9 @@
     @SuppressWarnings("unchecked")
     private static ISerializerDeserializer<ADateTime> datetimeSerde = AqlSerializerDeserializerProvider.INSTANCE
             .getSerializerDeserializer(BuiltinType.ADATETIME);
-    private static AMutableDateTime aDateTime = new AMutableDateTime(0, 0, 0, 0, 0, 0, 0, 0, 0);
-    private static String errorMessage = " can not be an instance of datetime";
+    private static AMutableDateTime aDateTime = new AMutableDateTime(0L);
 
-    private int time;
-    private byte timezone;
-    private short year;
-    private byte monthAndDay;
+    private long chrononTime;
 
     private ADateTimeSerializerDeserializer() {
     }
@@ -33,14 +30,9 @@
     @Override
     public ADateTime deserialize(DataInput in) throws HyracksDataException {
         try {
-            year = in.readShort();
-            monthAndDay = in.readByte();
-            timezone = in.readByte();
-            time = in.readInt();
+            chrononTime = in.readLong();
 
-            return new ADateTime(year >> 1, (year & 0x0001) * 8 + ((monthAndDay >> 5) & 0x07), monthAndDay & 0x1f,
-                    (short) ((time) * 20 % 216000000 / 3600000), (short) ((time) * 20 % 3600000 / 60000),
-                    (short) ((time) * 20 % 60000 / 1000), (short) ((time) * 20 % 1000), (short) 0, timezone);
+            return new ADateTime(chrononTime);
         } catch (IOException e) {
             throw new HyracksDataException(e);
         }
@@ -49,92 +41,14 @@
     @Override
     public void serialize(ADateTime instance, DataOutput out) throws HyracksDataException {
         try {
-            out.writeByte((byte) ((instance.getYear() << 1) >> 8));
-            out.writeByte((byte) ((byte) ((instance.getYear() << 1) & 0x00ff) + (byte) (instance.getMonth() >> 3)));
-            out.writeByte((byte) ((instance.getMonth() << 5) | (instance.getDay())));
-            out.writeByte((byte) instance.getTimeZone());
-            out.writeInt((((((instance.getHours() * 60) + instance.getMinutes()) * 60) + instance.getSeconds()) * 1000 + instance
-                    .getMilliseconds()) / 20);
+            out.writeLong(instance.getChrnonoTime());
         } catch (IOException e) {
             throw new HyracksDataException(e);
         }
     }
 
     public static void parse(String datetime, DataOutput out) throws HyracksDataException {
-        boolean positive = true;
-        int offset = 0;
-        byte timezonePart = 0;
-
-        if (datetime.charAt(offset) == '-') {
-            offset++;
-            positive = false;
-        }
-
-        if (datetime.charAt(offset + 4) != '-' || datetime.charAt(offset + 7) != '-')
-            throw new HyracksDataException(datetime + errorMessage);
-
-        short year = Short.parseShort(datetime.substring(offset, offset + 4));
-        short month = Short.parseShort(datetime.substring(offset + 5, offset + 7));
-        short day = Short.parseShort(datetime.substring(offset + 8, offset + 10));
-
-        if (year < 0 || year > 9999 || month < 0 || month > 12 || day < 0 || day > 31)
-            throw new HyracksDataException(datetime + errorMessage);
-
-        if (!positive)
-            year *= -1;
-
-        if (datetime.charAt(offset + 10) != 'T')
-            throw new HyracksDataException(datetime + errorMessage);
-
-        offset += 11;
-
-        if (datetime.charAt(offset + 2) != ':' || datetime.charAt(offset + 5) != ':')
-            throw new HyracksDataException(datetime + errorMessage);
-
-        short hour = Short.parseShort(datetime.substring(offset, offset + 2));
-        short minute = Short.parseShort(datetime.substring(offset + 3, offset + 5));
-        short second = Short.parseShort(datetime.substring(offset + 6, offset + 8));
-        short msecond = 0;
-
-        if (datetime.length() > offset + 8 && datetime.charAt(offset + 8) == ':') {
-            msecond = Short.parseShort(datetime.substring(offset + 9, offset + 12));
-            if (hour < 0 || hour > 24 || minute < 0 || minute > 59 || second < 0 || second > 59 || msecond < 0
-                    || msecond > 999 || (hour == 24 && (minute != 0 || second != 0 || msecond != 0)))
-                throw new HyracksDataException(datetime + errorMessage);
-            offset += 12;
-        } else {
-            if (hour < 0 || hour > 24 || minute < 0 || minute > 59 || second < 0 || second > 59
-                    || (hour == 24 && (minute != 0 || second != 0)))
-                throw new HyracksDataException(datetime + errorMessage);
-            offset += 8;
-        }
-
-        short timezoneHour = 0, timezoneMinute = 0;
-        if (datetime.length() > offset) {
-            if (datetime.charAt(offset) == 'Z')
-                timezonePart = 0;
-            else {
-                if ((datetime.charAt(offset) != '+' && datetime.charAt(offset) != '-')
-                        || (datetime.charAt(offset + 3) != ':'))
-                    throw new HyracksDataException(datetime + errorMessage);
-
-                timezoneHour = Short.parseShort(datetime.substring(offset + 1, offset + 3));
-                timezoneMinute = Short.parseShort(datetime.substring(offset + 4, offset + 6));
-
-                if (timezoneHour < 0
-                        || timezoneHour > 24
-                        || (timezoneHour == 24 && timezoneMinute != 0)
-                        || (timezoneMinute != 0 && timezoneMinute != 15 && timezoneMinute != 30 && timezoneMinute != 45))
-                    throw new HyracksDataException(datetime + errorMessage);
-
-                if (datetime.charAt(offset) == '-')
-                    timezonePart = (byte) -((timezoneHour * 4) + timezoneMinute / 15);
-                else
-                    timezonePart = (byte) ((timezoneHour * 4) + timezoneMinute / 15);
-            }
-
-        }
-        aDateTime.setValue(year, month, day, hour, minute, second, msecond, 0, timezonePart);
+        GregorianCalendarSystem.getInstance().parseStringForADatetime(datetime, aDateTime);
         datetimeSerde.serialize(aDateTime, out);
     }
 }
diff --git a/asterix-om/src/main/java/edu/uci/ics/asterix/om/base/ADateTime.java b/asterix-om/src/main/java/edu/uci/ics/asterix/om/base/ADateTime.java
index e300d78..47ce492 100644
--- a/asterix-om/src/main/java/edu/uci/ics/asterix/om/base/ADateTime.java
+++ b/asterix-om/src/main/java/edu/uci/ics/asterix/om/base/ADateTime.java
@@ -1,73 +1,17 @@
 package edu.uci.ics.asterix.om.base;
 
 import edu.uci.ics.asterix.common.exceptions.AsterixException;
+import edu.uci.ics.asterix.om.base.temporal.GregorianCalendarSystem;
 import edu.uci.ics.asterix.om.types.BuiltinType;
 import edu.uci.ics.asterix.om.types.IAType;
 import edu.uci.ics.asterix.om.visitors.IOMVisitor;
 
 public class ADateTime implements IAObject {
 
-    private static final int[] NUM_DAYS_IN_MONTH = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
+    protected long chrononTime;
 
-    protected int day;
-    protected int hour;
-    protected int minutes;
-    protected int month;
-    protected int seconds;
-    protected int timezone;
-    protected int year;
-    protected int milliseconds;
-    protected int microseconds;
-
-    public ADateTime(int year, int month, int day, int hour, int minutes, int seconds, int timezone) {
-        this.year = year;
-        this.month = month;
-        this.day = day;
-        this.hour = hour;
-        this.minutes = minutes;
-        this.seconds = seconds;
-        this.timezone = timezone;
-    }
-
-    public ADateTime(int year, int month, int day, int hour, int minutes, int seconds, int milliseconds,
-            int microseconds, int timezone) {
-        this.year = year;
-        this.month = month;
-        this.day = day;
-        this.hour = hour;
-        this.minutes = minutes;
-        this.seconds = seconds;
-        this.milliseconds = milliseconds;
-        this.microseconds = microseconds;
-        this.timezone = timezone;
-    }
-
-    public int getDay() {
-        return day;
-    }
-
-    public int getHours() {
-        return hour;
-    }
-
-    public int getMinutes() {
-        return minutes;
-    }
-
-    public int getMonth() {
-        return month;
-    }
-
-    public int getSeconds() {
-        return seconds;
-    }
-
-    public int getTimeZone() {
-        return timezone;
-    }
-
-    public int getYear() {
-        return year;
+    public ADateTime(long chrononTime) {
+        this.chrononTime = chrononTime;
     }
 
     @Override
@@ -75,125 +19,33 @@
         return BuiltinType.ADATETIME;
     }
 
-    public int getMicroseconds() {
-        return microseconds;
-    }
-
-    public int getMilliseconds() {
-        return milliseconds;
-    }
-
     public int compare(Object o) {
         if (!(o instanceof ADateTime)) {
             return -1;
         }
 
         ADateTime d = (ADateTime) o;
-        if (timezone != d.getTimeZone()) {
-            AMutableDateTime dt1 = new AMutableDateTime(year, month, day, hour, minutes, seconds, milliseconds,
-                    microseconds, timezone);
-            AMutableDateTime dt2 = new AMutableDateTime(d.getYear(), d.getMonth(), d.getDay(), d.getHours(),
-                    d.getMinutes(), d.getSeconds(), d.getMilliseconds(), d.getMicroseconds(), d.getTimeZone());
-            dt1.convertToUTC();
-            dt2.convertToUTC();
-
-            return dt1.tzEqualCompare(dt2);
-
-        }
-
-        return tzEqualCompare(d);
-    }
-
-    protected void convertToUTC() {
-        short tzMin = (short) ((timezone % 4) * 15);
-        short tzHr = (short) (timezone / 4);
-        minutes -= tzMin;
-        if (minutes >= 60) {
-            minutes %= 60;
-            hour += 1;
-        }
-        hour -= tzHr;
-        if (hour >= 24) {
-            hour %= 24;
-            day += 1;
-        }
-        if (isLeapYear(year) && month == 2) {
-            if (day >= 29) {
-                day %= 29;
-                month += 1;
-            }
+        if (this.chrononTime > d.chrononTime) {
+            return 1;
+        } else if (this.chrononTime < d.chrononTime) {
+            return -1;
         } else {
-            if (day >= NUM_DAYS_IN_MONTH[month - 1]) {
-                day %= NUM_DAYS_IN_MONTH[month - 1];
-                month += 1;
-            }
+            return 0;
         }
-
-        if (month >= 12) {
-            month %= 12;
-            year += 1;
-        }
-        timezone = 0;
-
-    }
-
-    protected static boolean isLeapYear(int year) {
-        if (year % 400 == 0) {
-            return true;
-        } else if (year % 100 == 0) {
-            return false;
-        } else if (year % 4 == 0) {
-            return true;
-        } else {
-            return false;
-        }
-    }
-
-    // comparison that assumes the timezones are the same!
-    protected int tzEqualCompare(ADateTime d) {
-        if (year != d.getYear()) {
-            return year - d.getYear();
-        }
-        if (month != d.getMonth()) {
-            return month - d.getMonth();
-        }
-        if (day != d.getDay()) {
-            return day - d.getDay();
-        }
-        if (hour != d.getHours()) {
-            return hour - d.getHours();
-        }
-        if (minutes != d.getMinutes()) {
-            return minutes - d.getMinutes();
-        }
-        if (seconds != d.getSeconds()) {
-            return seconds - d.getSeconds();
-        }
-        if (milliseconds != d.getMilliseconds()) {
-            return milliseconds - d.getMilliseconds();
-        }
-        if (microseconds != d.getMicroseconds()) {
-            return microseconds - d.getMicroseconds();
-        }
-
-        return 0;
     }
 
     public boolean equals(Object o) {
         if (!(o instanceof ADateTime)) {
             return false;
         } else {
-            ADateTime d = (ADateTime) o;
-            return d.getMicroseconds() == microseconds && d.getMilliseconds() == milliseconds
-                    && d.getSeconds() == seconds && d.getMinutes() == minutes && d.getHours() == hour
-                    && d.getDay() == day && d.getMonth() == month && d.getYear() == year && d.getTimeZone() == timezone;
+            ADateTime t = (ADateTime) o;
+            return t.chrononTime == this.chrononTime;
         }
     }
 
     @Override
     public int hashCode() {
-        return (((((((year * 31 + month) * 31 + day) * 31 + timezone) * 31 + hour) * 31 + minutes) * 31 + seconds) * 31 + milliseconds)
-                * 31 + microseconds;
+        return (int) (chrononTime ^ (chrononTime >>> 32));
     }
 
     @Override
@@ -213,8 +65,15 @@
 
     @Override
     public String toString() {
-        return "ADateTime: { " + year + "-" + month + "-" + day + ":" + hour + ":" + minutes + ":" + seconds + ":"
-                + milliseconds + ":" + microseconds + ":" + timezone + " }";
+        StringBuilder sbder = new StringBuilder();
+        sbder.append("ADateTime: { ");
+        GregorianCalendarSystem.getInstance().getStringRep(chrononTime, sbder);
+        sbder.append(" }");
+        return sbder.toString();
+    }
+
+    public long getChrnonoTime() {
+        return chrononTime;
     }
 
 }
diff --git a/asterix-om/src/main/java/edu/uci/ics/asterix/om/base/AMutableDateTime.java b/asterix-om/src/main/java/edu/uci/ics/asterix/om/base/AMutableDateTime.java
index 01e30a2..88553b0 100644
--- a/asterix-om/src/main/java/edu/uci/ics/asterix/om/base/AMutableDateTime.java
+++ b/asterix-om/src/main/java/edu/uci/ics/asterix/om/base/AMutableDateTime.java
@@ -2,22 +2,12 @@
 
 public class AMutableDateTime extends ADateTime {
 
-    public AMutableDateTime(int year, int month, int day, int hour, int minutes, int seconds, int milliseconds,
-            int microseconds, int timezone) {
-        super(year, month, day, hour, minutes, seconds, milliseconds, microseconds, timezone);
+    public AMutableDateTime(long chrononTime) {
+        super(chrononTime);
     }
 
-    public void setValue(int year, int month, int day, int hour, int minutes, int seconds, int milliseconds,
-            int microseconds, int timezone) {
-        this.year = year;
-        this.month = month;
-        this.day = day;
-        this.hour = hour;
-        this.minutes = minutes;
-        this.seconds = seconds;
-        this.milliseconds = milliseconds;
-        this.microseconds = microseconds;
-        this.timezone = timezone;
+    public void setValue(long chrononTime) {
+        this.chrononTime = chrononTime;
     }
 
 }
diff --git a/asterix-om/src/main/java/edu/uci/ics/asterix/om/base/temporal/GregorianCalendarSystem.java b/asterix-om/src/main/java/edu/uci/ics/asterix/om/base/temporal/GregorianCalendarSystem.java
new file mode 100644
index 0000000..707daaa
--- /dev/null
+++ b/asterix-om/src/main/java/edu/uci/ics/asterix/om/base/temporal/GregorianCalendarSystem.java
@@ -0,0 +1,783 @@
+/*
+ * Copyright 2009-2012 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Joda API (http://joda-time.sourceforge.net/) is under the protection of:
+ * 
+ * Copyright 2001-2005 Stephen Colebourne
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.asterix.om.base.temporal;
+
+import java.io.DataOutput;
+import java.io.IOException;
+
+import edu.uci.ics.asterix.om.base.AMutableDateTime;
+import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+
+/**
+ * A simple implementation of the Gregorian calendar system.
+ * <p/>
+ */
+public class GregorianCalendarSystem implements ICalendarSystem {
+
+    private static final int[] DAYS_OF_MONTH_ORDI = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
+    private static final int[] DAYS_OF_MONTH_LEAP = { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
+
+    private static final int[] DAYS_SINCE_MONTH_BEGIN_ORDI = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
+
+    private static final String ERROR_FORMAT = ": unrecognizable datetime format.";
+
+    private static final int CHRONON_OF_SECOND = 1000;
+    private static final int CHRONON_OF_MINUTE = 60 * CHRONON_OF_SECOND;
+    private static final int CHRONON_OF_HOUR = 60 * CHRONON_OF_MINUTE;
+    private static final long CHRONON_OF_DAY = 24 * CHRONON_OF_HOUR;
+
+    /**
+     * Minimum feasible value of each field
+     */
+    private static final int[] FIELD_MINS = { Integer.MIN_VALUE, // year
+            1, // month
+            1, // day
+            0, // hour
+            0, // minute
+            0, // second
+            0 // millisecond
+    };
+
+    private static final int[] FIELD_MAXS = { Integer.MAX_VALUE, // year
+            12, // month
+            31, // day
+            23, // hour
+            59, // minute
+            59, // second
+            999 // millisecond
+    };
+
+    /**
+     * From Joda API: GregorianChronology.java
+     */
+    private static final long CHRONON_OF_YEAR = (long) (365.2425 * CHRONON_OF_DAY);
+
+    /**
+     * From Joda API: GregorianChronology.java
+     */
+    private static final int DAYS_0000_TO_1970 = 719527;
+
+    private static final GregorianCalendarSystem instance = new GregorianCalendarSystem();
+
+    private GregorianCalendarSystem() {
+    }
+
+    public static GregorianCalendarSystem getInstance() {
+        return instance;
+    }
+
+    /**
+     * Check whether the given date time value is a valid date time following the gregorian calendar system.
+     * 
+     * @param fields
+     * @return
+     */
+    public boolean validate(int year, int month, int day, int hour, int min, int sec, int millis) {
+        // Check whether each field is within the value domain
+        if (year < FIELD_MINS[0] || year > FIELD_MAXS[0])
+            return false;
+        if (month < FIELD_MINS[1] || month > FIELD_MAXS[1])
+            return false;
+        if (day < FIELD_MINS[2] || day > FIELD_MAXS[2])
+            return false;
+        if (hour < FIELD_MINS[3] || hour > FIELD_MAXS[3])
+            return false;
+        if (min < FIELD_MINS[4] || min > FIELD_MAXS[4])
+            return false;
+        if (sec < FIELD_MINS[5] || sec > FIELD_MAXS[5])
+            return false;
+        if (millis < FIELD_MINS[6] || millis > FIELD_MAXS[6])
+            return false;
+
+        // Check whether leap month.
+        if (month == 2)
+            if (isLeapYear(year)) {
+                if (month > DAYS_OF_MONTH_LEAP[1])
+                    return false;
+            } else {
+                if (month > DAYS_OF_MONTH_ORDI[1])
+                    return false;
+            }
+        return true;
+    }
+
+    /**
+     * Check whether the given time zone value is a valid time zone following the gregorian calendar system.
+     * 
+     * @param timezone
+     * @return
+     */
+    public boolean validateTimeZone(int timezone) {
+        short tzMin = (short) ((timezone % 4) * 15);
+
+        if (tzMin < -60 || tzMin >= 60) {
+            return false;
+        }
+
+        short tzHr = (short) (timezone / 4);
+
+        if (tzHr < -12 && tzHr > 14) {
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Validate the given chronon time and time zone.
+     * 
+     * @param year
+     * @param month
+     * @param day
+     * @param hour
+     * @param min
+     * @param sec
+     * @param millis
+     * @param timezone
+     * @return
+     */
+    public boolean validate(int year, int month, int day, int hour, int min, int sec, int millis, int timezone) {
+        return validate(year, month, day, hour, min, sec, millis) && validateTimeZone(timezone);
+    }
+
+    /**
+     * Get the chronon time of the given date time and time zone.
+     * 
+     * @param year
+     * @param month
+     * @param day
+     * @param hour
+     * @param min
+     * @param sec
+     * @param millis
+     * @param timezone
+     * @return
+     */
+    public long getChronon(int year, int month, int day, int hour, int min, int sec, int millis, int timezone) {
+        // Added milliseconds for all fields but month and day
+        long chrononTime = chrononizeBeginningOfYear(year) + (hour - timezone / 4) * CHRONON_OF_HOUR
+                + (min - (timezone % 4) * 15) * CHRONON_OF_MINUTE + sec * CHRONON_OF_SECOND + millis;
+
+        // Added milliseconds for days of the month. 
+        chrononTime += (day - 1 + DAYS_SINCE_MONTH_BEGIN_ORDI[month - 1]) * CHRONON_OF_DAY;
+
+        // Adjust the leap year
+        if (month > 2 && isLeapYear(year)) {
+            chrononTime += CHRONON_OF_DAY;
+        }
+
+        return chrononTime;
+    }
+
+    /**
+     * Get the ISO8601 compatible representation of the given chronon time, using the extended form as<br/>
+     * [-]YYYY-MM-DDThh:mm:ss.xxx[+|-]hh:mm
+     */
+    @Override
+    public void getStringRep(long chrononTime, StringBuilder sbder) {
+        getExtendStringRepWithTimezone(chrononTime, 0, sbder);
+    }
+
+    public void getStringRep(long chrononTime, DataOutput out) throws IOException {
+        int year = getYear(chrononTime);
+        int month = getMonthOfYear(chrononTime, year);
+
+        out.writeUTF(String.format(year < 0 ? "%05d" : "%04d", year) + "-" + String.format("%02d", month) + "-"
+                + String.format("%02d", getDayOfMonthYear(chrononTime, year, month)) + "T"
+                + String.format("%02d", getHourOfDay(chrononTime)) + ":"
+                + String.format("%02d", getMinOfHour(chrononTime)) + ":"
+                + String.format("%02d", getSecOfMin(chrononTime)) + "."
+                + String.format("%03d", getMillisOfSec(chrononTime)) + "Z");
+    }
+
+    public void getExtendStringRepWithTimezone(long chrononTime, int timezone, StringBuilder sbder) {
+        int year = getYear(chrononTime);
+        int month = getMonthOfYear(chrononTime, year);
+
+        sbder.append(String.format(year < 0 ? "%05d" : "%04d", year)).append("-").append(String.format("%02d", month)).append("-")
+                .append(String.format("%02d", getDayOfMonthYear(chrononTime, year, month))).append("T")
+                .append(String.format("%02d", getHourOfDay(chrononTime))).append(":")
+                .append(String.format("%02d", getMinOfHour(chrononTime))).append(":")
+                .append(String.format("%02d", getSecOfMin(chrononTime))).append(".")
+                .append(String.format("%03d", getMillisOfSec(chrononTime)));
+
+        if (timezone == 0) {
+            sbder.append("Z");
+        } else {
+            short tzMin = (short) ((timezone % 4) * 15);
+            short tzHr = (short) (timezone / 4);
+            sbder.append((tzHr >= 0 ? "+" : "-")).append(String.format("%02d", (tzHr < 0 ? -tzHr : tzHr))).append(":")
+                    .append(String.format("%02d", tzMin));
+        }
+    }
+
+    public void getBasicStringRepWithTimezone(long chrononTime, int timezone, StringBuilder sbder) {
+        int year = getYear(chrononTime);
+        int month = getMonthOfYear(chrononTime, year);
+
+        sbder.append(String.format(year < 0 ? "%05d" : "%04d", year)).append(String.format("%02d", month))
+                .append(String.format("%02d", getDayOfMonthYear(chrononTime, year, month))).append("T")
+                .append(String.format("%02d", getHourOfDay(chrononTime)))
+                .append(String.format("%02d", getMinOfHour(chrononTime)))
+                .append(String.format("%02d", getSecOfMin(chrononTime)))
+                .append(String.format("%03d", getMillisOfSec(chrononTime)));
+
+        if (timezone == 0) {
+            sbder.append("Z");
+        } else {
+            short tzMin = (short) ((timezone % 4) * 15);
+            short tzHr = (short) (timezone / 4);
+            sbder.append((tzHr >= 0 ? "+" : "-")).append(String.format("%02d", (tzHr < 0 ? -tzHr : tzHr)))
+                    .append(String.format("%02d", tzMin));
+        }
+    }
+
+    /* (non-Javadoc)
+     * @see edu.uci.ics.asterix.om.base.temporal.ICalendarSystem#parseStringRep(java.lang.String, java.io.DataOutput)
+     */
+    @Override
+    public void parseStringRep(String datetime, DataOutput out) throws HyracksDataException {
+        int offset = 0;
+        int year, month, day, hour, min, sec, millis = 0;
+        int timezone = 0;
+        boolean positive = true;
+        if (datetime.contains(":")) {
+            // parse extended form
+            if (datetime.charAt(offset) == '-') {
+                offset++;
+                positive = false;
+            }
+
+            if (datetime.charAt(offset + 4) != '-' || datetime.charAt(offset + 7) != '-')
+                throw new HyracksDataException(datetime + ERROR_FORMAT);
+
+            year = Short.parseShort(datetime.substring(offset, offset + 4));
+            month = Short.parseShort(datetime.substring(offset + 5, offset + 7));
+            day = Short.parseShort(datetime.substring(offset + 8, offset + 10));
+
+            if (!positive)
+                year *= -1;
+
+            offset += 11;
+
+            if (datetime.charAt(offset + 2) != ':' || datetime.charAt(offset + 5) != ':')
+                throw new HyracksDataException(datetime + ERROR_FORMAT);
+
+            hour = Short.parseShort(datetime.substring(offset, offset + 2));
+            min = Short.parseShort(datetime.substring(offset + 3, offset + 5));
+            sec = Short.parseShort(datetime.substring(offset + 6, offset + 8));
+
+            offset += 8;
+            if (datetime.length() > offset && datetime.charAt(offset) == '.') {
+                millis = Short.parseShort(datetime.substring(offset + 1, offset + 4));
+                offset += 4;
+            }
+
+            if (datetime.length() > offset) {
+                if (datetime.charAt(offset) != 'Z') {
+                    if ((datetime.charAt(offset) != '+' && datetime.charAt(offset) != '-')
+                            || (datetime.charAt(offset + 3) != ':'))
+                        throw new HyracksDataException(datetime + ERROR_FORMAT);
+
+                    short timezoneHour = Short.parseShort(datetime.substring(offset + 1, offset + 3));
+                    short timezoneMinute = Short.parseShort(datetime.substring(offset + 4, offset + 6));
+
+                    if (datetime.charAt(offset) == '-')
+                        timezone = (byte) -((timezoneHour * 4) + timezoneMinute / 15);
+                    else
+                        timezone = (byte) ((timezoneHour * 4) + timezoneMinute / 15);
+                }
+            }
+
+        } else {
+            // parse basic form
+            if (datetime.charAt(offset) == '-') {
+                offset++;
+                positive = false;
+            }
+
+            year = Short.parseShort(datetime.substring(offset, offset + 4));
+            month = Short.parseShort(datetime.substring(offset + 4, offset + 6));
+            day = Short.parseShort(datetime.substring(offset + 6, offset + 8));
+
+            if (!positive)
+                day *= -1;
+
+            offset += 9;
+
+            hour = Short.parseShort(datetime.substring(offset, offset + 2));
+            min = Short.parseShort(datetime.substring(offset + 2, offset + 4));
+            sec = Short.parseShort(datetime.substring(offset + 4, offset + 6));
+
+            offset += 6;
+            if (datetime.length() > offset && datetime.charAt(offset) == '.') {
+                millis = Short.parseShort(datetime.substring(offset + 1, offset + 4));
+                offset += 4;
+            }
+
+            if (datetime.length() > offset) {
+                if (datetime.charAt(offset) != 'Z') {
+                    if ((datetime.charAt(offset) != '+' && datetime.charAt(offset) != '-'))
+                        throw new HyracksDataException(datetime + ERROR_FORMAT);
+
+                    short timezoneHour = Short.parseShort(datetime.substring(offset + 1, offset + 3));
+                    short timezoneMinute = Short.parseShort(datetime.substring(offset + 3, offset + 5));
+
+                    if (datetime.charAt(offset) == '-')
+                        timezone = (byte) -((timezoneHour * 4) + timezoneMinute / 15);
+                    else
+                        timezone = (byte) ((timezoneHour * 4) + timezoneMinute / 15);
+                }
+            }
+        }
+
+        if (!validate(year, month, day, hour, min, sec, millis, timezone)) {
+            throw new HyracksDataException(datetime + ERROR_FORMAT);
+        }
+
+        long chrononTime = getChronon(year, month, day, hour, min, sec, (int) millis, timezone);
+
+        try {
+            out.writeLong(chrononTime);
+            out.writeInt(timezone);
+        } catch (IOException e) {
+            throw new HyracksDataException(e.toString());
+        }
+    }
+
+    public void parseStringForADatetime(String datetime, AMutableDateTime aMutableDatetime) throws HyracksDataException {
+        int offset = 0;
+        int year, month, day, hour, min, sec, millis = 0;
+        int timezone = 0;
+        boolean positive = true;
+        if (datetime.contains(":")) {
+            // parse extended form
+            if (datetime.charAt(offset) == '-') {
+                offset++;
+                positive = false;
+            }
+
+            if (datetime.charAt(offset + 4) != '-' || datetime.charAt(offset + 7) != '-')
+                throw new HyracksDataException(datetime + ERROR_FORMAT);
+
+            year = Short.parseShort(datetime.substring(offset, offset + 4));
+            month = Short.parseShort(datetime.substring(offset + 5, offset + 7));
+            day = Short.parseShort(datetime.substring(offset + 8, offset + 10));
+
+            if (!positive)
+                year *= -1;
+
+            offset += 11;
+
+            if (datetime.charAt(offset + 2) != ':' || datetime.charAt(offset + 5) != ':')
+                throw new HyracksDataException(datetime + ERROR_FORMAT);
+
+            hour = Short.parseShort(datetime.substring(offset, offset + 2));
+            min = Short.parseShort(datetime.substring(offset + 3, offset + 5));
+            sec = Short.parseShort(datetime.substring(offset + 6, offset + 8));
+
+            offset += 8;
+            if (datetime.length() > offset && datetime.charAt(offset) == '.') {
+                millis = Short.parseShort(datetime.substring(offset + 1, offset + 4));
+                offset += 4;
+            }
+
+            if (datetime.length() > offset) {
+                if (datetime.charAt(offset) != 'Z') {
+                    if ((datetime.charAt(offset) != '+' && datetime.charAt(offset) != '-')
+                            || (datetime.charAt(offset + 3) != ':'))
+                        throw new HyracksDataException(datetime + ERROR_FORMAT);
+
+                    short timezoneHour = Short.parseShort(datetime.substring(offset + 1, offset + 3));
+                    short timezoneMinute = Short.parseShort(datetime.substring(offset + 4, offset + 6));
+
+                    if (datetime.charAt(offset) == '-')
+                        timezone = (byte) -((timezoneHour * 4) + timezoneMinute / 15);
+                    else
+                        timezone = (byte) ((timezoneHour * 4) + timezoneMinute / 15);
+                }
+            }
+
+        } else {
+            // parse basic form
+            if (datetime.charAt(offset) == '-') {
+                offset++;
+                positive = false;
+            }
+
+            year = Short.parseShort(datetime.substring(offset, offset + 4));
+            month = Short.parseShort(datetime.substring(offset + 4, offset + 6));
+            day = Short.parseShort(datetime.substring(offset + 6, offset + 8));
+
+            if (!positive)
+                day *= -1;
+
+            offset += 9;
+
+            hour = Short.parseShort(datetime.substring(offset, offset + 2));
+            min = Short.parseShort(datetime.substring(offset + 2, offset + 4));
+            sec = Short.parseShort(datetime.substring(offset + 4, offset + 6));
+
+            offset += 6;
+            if (datetime.length() > offset && datetime.charAt(offset) == '.') {
+                millis = Short.parseShort(datetime.substring(offset + 1, offset + 4));
+                offset += 4;
+            }
+
+            if (datetime.length() > offset) {
+                if (datetime.charAt(offset) != 'Z') {
+                    if ((datetime.charAt(offset) != '+' && datetime.charAt(offset) != '-'))
+                        throw new HyracksDataException(datetime + ERROR_FORMAT);
+
+                    short timezoneHour = Short.parseShort(datetime.substring(offset + 1, offset + 3));
+                    short timezoneMinute = Short.parseShort(datetime.substring(offset + 3, offset + 5));
+
+                    if (datetime.charAt(offset) == '-')
+                        timezone = (byte) -((timezoneHour * 4) + timezoneMinute / 15);
+                    else
+                        timezone = (byte) ((timezoneHour * 4) + timezoneMinute / 15);
+                }
+            }
+        }
+
+        if (!validate(year, month, day, hour, min, sec, millis, timezone)) {
+            throw new HyracksDataException(datetime + ERROR_FORMAT);
+        }
+
+        aMutableDatetime.setValue(getChronon(year, month, day, hour, min, sec, (int) millis, timezone));
+    }
+
+    public void parseStringForADatetime(byte[] datetime, int offset, AMutableDateTime aMutableDatetime)
+            throws AlgebricksException {
+        int year, month, day, hour, min, sec, millis = 0;
+        int timezone = 0;
+        boolean positive = true;
+        boolean isExtendedForm = false;
+        if (datetime[offset + 13] == ':' || datetime[offset + 14] == ':') {
+            isExtendedForm = true;
+        }
+        if (isExtendedForm) {
+            // parse extended form
+            if (datetime[offset] == '-') {
+                offset++;
+                positive = false;
+            }
+
+            if (datetime[offset + 4] != '-' || datetime[offset + 7] != '-')
+                throw new AlgebricksException(datetime + ERROR_FORMAT);
+
+            year = getValue(datetime, offset, 4);
+            month = getValue(datetime, offset + 5, 2);
+            day = getValue(datetime, offset + 8, 2);
+
+            if (!positive)
+                year *= -1;
+
+            offset += 11;
+
+            if (datetime[offset + 2] != ':' || datetime[offset + 5] != ':')
+                throw new AlgebricksException(datetime + ERROR_FORMAT);
+
+            hour = getValue(datetime, offset, 2);
+            min = getValue(datetime, offset + 3, 2);
+            sec = getValue(datetime, offset + 6, 2);
+
+            offset += 8;
+            if (datetime.length > offset && datetime[offset] == '.') {
+                millis = getValue(datetime, offset + 1, 3);
+                offset += 4;
+            }
+
+            if (datetime.length > offset) {
+                if (datetime[offset] != 'Z') {
+                    if ((datetime[offset] != '+' && datetime[offset] != '-') || (datetime[offset + 3] != ':'))
+                        throw new AlgebricksException(datetime + ERROR_FORMAT);
+
+                    short timezoneHour = getValue(datetime, offset + 1, 2);
+                    short timezoneMinute = getValue(datetime, offset + 4, 2);
+
+                    if (datetime[offset] == '-')
+                        timezone = (byte) -((timezoneHour * 4) + timezoneMinute / 15);
+                    else
+                        timezone = (byte) ((timezoneHour * 4) + timezoneMinute / 15);
+                }
+            }
+
+        } else {
+            // parse basic form
+            if (datetime[offset] == '-') {
+                offset++;
+                positive = false;
+            }
+
+            year = getValue(datetime, offset, 4);
+            month = getValue(datetime, offset + 4, 2);
+            day = getValue(datetime, offset + 6, 2);
+
+            if (!positive)
+                day *= -1;
+
+            offset += 9;
+
+            hour = getValue(datetime, offset, 2);
+            min = getValue(datetime, offset + 2, 2);
+            sec = getValue(datetime, offset + 4, 2);
+
+            offset += 6;
+            if (datetime.length > offset && datetime[offset] == '.') {
+                millis = getValue(datetime, offset + 1, 3);
+                offset += 4;
+            }
+
+            if (datetime.length > offset) {
+                if (datetime[offset] != 'Z') {
+                    if ((datetime[offset] != '+' && datetime[offset] != '-'))
+                        throw new AlgebricksException(datetime + ERROR_FORMAT);
+
+                    short timezoneHour = getValue(datetime, offset + 1, 2);
+                    short timezoneMinute = getValue(datetime, offset + 3, 2);
+
+                    if (datetime[offset] == '-')
+                        timezone = (byte) -((timezoneHour * 4) + timezoneMinute / 15);
+                    else
+                        timezone = (byte) ((timezoneHour * 4) + timezoneMinute / 15);
+                }
+            }
+        }
+
+        if (!validate(year, month, day, hour, min, sec, millis, timezone)) {
+            throw new AlgebricksException(datetime + ERROR_FORMAT);
+        }
+
+        aMutableDatetime.setValue(getChronon(year, month, day, hour, min, sec, (int) millis, timezone));
+    }
+
+    private short getValue(byte[] b, int offset, int numberOfDigits) throws AlgebricksException {
+        short value = 0;
+        for (int i = 0; i < numberOfDigits; i++) {
+            if ((b[offset] >= '0' && b[offset] <= '9'))
+                value = (short) (value * 10 + b[offset++] - '0');
+            else
+                throw new AlgebricksException(ERROR_FORMAT);
+
+        }
+        return value;
+    }
+
+    /**
+     * Check whether a given year is a leap year.
+     * 
+     * @param year
+     * @return
+     */
+    protected boolean isLeapYear(int year) {
+        return ((year & 3) == 0) && ((year % 100) != 0 || (year % 400) == 0);
+    }
+
+    /**
+     * From Joda library GregorianChronology class: The basic calculation is
+     * (y / 4) - (y / 100) + (y / 400). <br/>
+     * Use y >> 2 ( (y + 3) >> 2 for negative y value) to replace y / 4 reveals eliminates two divisions.
+     * 
+     * @param year
+     * @return
+     */
+    private long chrononizeBeginningOfYear(int year) {
+        int leapYears = year / 100;
+        if (year < 0) {
+            // From Joda library GregorianChronology class
+            // The basic calculation is (y / 4) - (y / 100) + (y / 400)
+            // Use (y + 3) >> 2 to replace y / 4 reveals eliminates two divisions.
+            leapYears = ((year + 3) >> 2) - leapYears + ((leapYears + 3) >> 2) - 1;
+        } else {
+            leapYears = (year >> 2) - leapYears + (leapYears >> 2);
+            if (isLeapYear(year)) {
+                leapYears--;
+            }
+        }
+        return (year * 365L + (leapYears - DAYS_0000_TO_1970)) * CHRONON_OF_DAY;
+    }
+
+    /**
+     * Get the year for the given chronon time.
+     * <p/>
+     * This code is directly from the Joda library BadicChronology.java.<br/>
+     * The original authers are Stephen Colebourne, Brain S O'Neill and Guy Allard, and modified by JArod Wen on May 7th, 2012.
+     * 
+     * @param chrononTime
+     * @return
+     */
+    public int getYear(long chrononTime) {
+        // Get an initial estimate of the year, and the millis value that
+        // represents the start of that year. Then verify estimate and fix if
+        // necessary.
+
+        // Initial estimate uses values divided by two to avoid overflow.
+        long unitMillis = CHRONON_OF_YEAR / 2;
+        long i2 = (chrononTime >> 1) + (1970L * CHRONON_OF_YEAR) / 2;
+        if (i2 < 0) {
+            i2 = i2 - unitMillis + 1;
+        }
+        int year = (int) (i2 / unitMillis);
+
+        long yearStart = chrononizeBeginningOfYear(year);
+        long diff = chrononTime - yearStart;
+
+        if (diff < 0) {
+            year--;
+        } else if (diff >= CHRONON_OF_DAY * 365L) {
+            // One year may need to be added to fix estimate.
+            long oneYear;
+            if (isLeapYear(year)) {
+                oneYear = CHRONON_OF_DAY * 366L;
+            } else {
+                oneYear = CHRONON_OF_DAY * 365L;
+            }
+
+            yearStart += oneYear;
+
+            if (yearStart <= chrononTime) {
+                // Didn't go too far, so actually add one year.
+                year++;
+            }
+        }
+
+        return year;
+    }
+
+    /**
+     * Get the month of the year for the given chronon time and the year.
+     * <p/>
+     * This code is directly from the Joda library BasicGJChronology.java.<br/>
+     * The original authers are Stephen Colebourne, Brain S O'Neill and Guy Allard, and modified by JArod Wen on May 7th, 2012.
+     * <p/>
+     * 
+     * @param millis
+     * @param year
+     * @return
+     */
+    public int getMonthOfYear(long millis, int year) {
+        // Perform a binary search to get the month. To make it go even faster,
+        // compare using ints instead of longs. The number of milliseconds per
+        // year exceeds the limit of a 32-bit int's capacity, so divide by
+        // 1024. No precision is lost (except time of day) since the number of
+        // milliseconds per day contains 1024 as a factor. After the division,
+        // the instant isn't measured in milliseconds, but in units of
+        // (128/125)seconds.
+
+        int i = (int) ((millis - chrononizeBeginningOfYear(year)) >> 10);
+
+        // There are 86400000 milliseconds per day, but divided by 1024 is
+        // 84375. There are 84375 (128/125)seconds per day.
+
+        return (isLeapYear(year)) ? ((i < 182 * 84375) ? ((i < 91 * 84375) ? ((i < 31 * 84375) ? 1
+                : (i < 60 * 84375) ? 2 : 3) : ((i < 121 * 84375) ? 4 : (i < 152 * 84375) ? 5 : 6))
+                : ((i < 274 * 84375) ? ((i < 213 * 84375) ? 7 : (i < 244 * 84375) ? 8 : 9) : ((i < 305 * 84375) ? 10
+                        : (i < 335 * 84375) ? 11 : 12)))
+                : ((i < 181 * 84375) ? ((i < 90 * 84375) ? ((i < 31 * 84375) ? 1 : (i < 59 * 84375) ? 2 : 3)
+                        : ((i < 120 * 84375) ? 4 : (i < 151 * 84375) ? 5 : 6))
+                        : ((i < 273 * 84375) ? ((i < 212 * 84375) ? 7 : (i < 243 * 84375) ? 8 : 9)
+                                : ((i < 304 * 84375) ? 10 : (i < 334 * 84375) ? 11 : 12)));
+    }
+
+    /**
+     * Get the day of the given month and year for the input chronon time.
+     * <p/>
+     * This function is directly from Joda Library BasicChronology.java.<br/>
+     * The original authers are Stephen Colebourne, Brain S O'Neill and Guy Allard, and modified by JArod Wen on May 7th, 2012.
+     * <p/>
+     * 
+     * @param millis
+     * @param year
+     * @param month
+     * @return
+     */
+    public int getDayOfMonthYear(long millis, int year, int month) {
+        long dateMillis = chrononizeBeginningOfYear(year);
+        dateMillis += DAYS_SINCE_MONTH_BEGIN_ORDI[month - 1] * CHRONON_OF_DAY;
+        if (isLeapYear(year) && month > 2) {
+            dateMillis += CHRONON_OF_DAY;
+        }
+        return (int) ((millis - dateMillis) / CHRONON_OF_DAY) + 1;
+    }
+
+    public int getHourOfDay(long millis) {
+        int hour = (int) ((millis % CHRONON_OF_DAY) / CHRONON_OF_HOUR);
+
+        if (millis < 0) {
+            if (millis % CHRONON_OF_HOUR == 0) {
+                if (hour < 0) {
+                    hour += 24;
+                }
+            } else {
+                hour += 23;
+            }
+        }
+        return hour;
+    }
+
+    public int getMinOfHour(long millis) {
+        int min = (int) ((millis % CHRONON_OF_HOUR) / CHRONON_OF_MINUTE);
+        if (millis < 0) {
+            if (millis % CHRONON_OF_MINUTE == 0) {
+                if (min < 0) {
+                    min += 60;
+                }
+            } else {
+                min += 59;
+            }
+        }
+        return min;
+    }
+
+    public int getSecOfMin(long millis) {
+        int sec = (int) ((millis % CHRONON_OF_MINUTE) / CHRONON_OF_SECOND);
+        if (millis < 0) {
+            if (millis % CHRONON_OF_SECOND == 0) {
+                if (sec < 0) {
+                    sec += 60;
+                }
+            } else {
+                sec += 59;
+            }
+        }
+        return sec;
+    }
+
+    public int getMillisOfSec(long millis) {
+        int ms = (int) (millis % CHRONON_OF_SECOND);
+        if (millis < 0 && ms < 0) {
+            ms += 1000;
+        }
+        return ms;
+    }
+}
diff --git a/asterix-om/src/main/java/edu/uci/ics/asterix/om/base/temporal/ICalendarSystem.java b/asterix-om/src/main/java/edu/uci/ics/asterix/om/base/temporal/ICalendarSystem.java
new file mode 100644
index 0000000..c6b7c84
--- /dev/null
+++ b/asterix-om/src/main/java/edu/uci/ics/asterix/om/base/temporal/ICalendarSystem.java
@@ -0,0 +1,20 @@
+package edu.uci.ics.asterix.om.base.temporal;
+
+import java.io.DataOutput;
+import java.io.IOException;
+
+import edu.uci.ics.asterix.om.base.IAObject;
+import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+
+public interface ICalendarSystem {
+
+    public boolean validate(int year, int month, int day, int hour, int min, int sec, int millis, int timezone);
+
+    public long getChronon(int year, int month, int day, int hour, int min, int sec, int millis, int timezone);
+
+    public void getStringRep(long chrononTime, StringBuilder sbder);
+
+    public void parseStringRep(String stringRep, DataOutput out) throws HyracksDataException;
+
+}
diff --git a/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/constructors/ADateTimeConstructorDescriptor.java b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/constructors/ADateTimeConstructorDescriptor.java
index a7efb16..f3fcc73 100644
--- a/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/constructors/ADateTimeConstructorDescriptor.java
+++ b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/constructors/ADateTimeConstructorDescriptor.java
@@ -8,6 +8,7 @@
 import edu.uci.ics.asterix.om.base.ADateTime;
 import edu.uci.ics.asterix.om.base.AMutableDateTime;
 import edu.uci.ics.asterix.om.base.ANull;
+import edu.uci.ics.asterix.om.base.temporal.GregorianCalendarSystem;
 import edu.uci.ics.asterix.om.types.ATypeTag;
 import edu.uci.ics.asterix.om.types.BuiltinType;
 import edu.uci.ics.asterix.runtime.evaluators.base.AbstractScalarFunctionDynamicDescriptor;
@@ -42,11 +43,8 @@
                     private ArrayBackedValueStorage outInput = new ArrayBackedValueStorage();
                     private IEvaluator eval = args[0].createEvaluator(outInput);
                     private int offset;
-                    private short hour, minute, second, msecond, year, month, day, timezoneHour, timezoneMinute, value;
-                    private byte timezonePart = 0;
-                    private boolean positive = true;
                     private String errorMessage = "This can not be an instance of datetime";
-                    private AMutableDateTime aDateTime = new AMutableDateTime(0, 0, 0, 0, 0, 0, 0, 0, 0);
+                    private AMutableDateTime aDateTime = new AMutableDateTime(0L);
                     @SuppressWarnings("unchecked")
                     private ISerializerDeserializer<ADateTime> datetimeSerde = AqlSerializerDeserializerProvider.INSTANCE
                             .getSerializerDeserializer(BuiltinType.ADATETIME);
@@ -64,77 +62,8 @@
                             if (serString[0] == SER_STRING_TYPE_TAG) {
 
                                 offset = 3;
-                                if (serString[offset] == '-') {
-                                    offset++;
-                                    positive = false;
-                                }
-
-                                if (serString[offset + 4] != '-' || serString[offset + 7] != '-')
-                                    throw new AlgebricksException(errorMessage);
-
-                                year = getValue(serString, offset, 4);
-                                month = getValue(serString, offset + 5, 2);
-                                day = getValue(serString, offset + 8, 2);
-
-                                if (year < 0 || year > 9999 || month < 0 || month > 12 || day < 0 || day > 31)
-                                    throw new AlgebricksException(errorMessage);
-
-                                if (!positive)
-                                    year *= -1;
-
-                                if (serString[offset + 10] != 'T')
-                                    throw new AlgebricksException(errorMessage);
-
-                                offset += 11;
-
-                                if (serString[offset + 2] != ':' || serString[offset + 5] != ':')
-                                    throw new AlgebricksException(errorMessage);
-
-                                hour = getValue(serString, offset, 2);
-                                minute = getValue(serString, offset + 3, 2);
-                                second = getValue(serString, offset + 6, 2);
-
-                                msecond = 0;
-                                if (serString[offset + 8] == ':') {
-                                    msecond = getValue(serString, offset + 9, 3);
-                                    if (hour < 0 || hour > 24 || minute < 0 || minute > 59 || second < 0 || second > 59
-                                            || msecond < 0 || msecond > 999
-                                            || (hour == 24 && (minute != 0 || second != 0 || msecond != 0)))
-                                        throw new AlgebricksException(errorMessage);
-                                    offset += 12;
-                                } else {
-                                    if (hour < 0 || hour > 24 || minute < 0 || minute > 59 || second < 0 || second > 59
-                                            || (hour == 24 && (minute != 0 || second != 0)))
-                                        throw new AlgebricksException(errorMessage);
-                                    offset += 8;
-                                }
-
-                                if (outInput.getLength() > offset) {
-                                    if (serString[offset] == 'Z')
-                                        timezonePart = 0;
-                                    else {
-                                        if ((serString[offset] != '+' && serString[offset] != '-')
-                                                || (serString[offset + 3] != ':'))
-                                            throw new AlgebricksException(errorMessage);
-
-                                        timezoneHour = getValue(serString, offset + 1, 2);
-                                        timezoneMinute = getValue(serString, offset + 4, 2);
-
-                                        if (timezoneHour < 0
-                                                || timezoneHour > 24
-                                                || (timezoneHour == 24 && timezoneMinute != 0)
-                                                || (timezoneMinute != 0 && timezoneMinute != 15 && timezoneMinute != 30 && timezoneMinute != 45))
-                                            throw new AlgebricksException(errorMessage);
-
-                                        if (serString[offset] == '-')
-                                            timezonePart = (byte) -((timezoneHour * 4) + timezoneMinute / 15);
-                                        else
-                                            timezonePart = (byte) ((timezoneHour * 4) + timezoneMinute / 15);
-                                    }
-
-                                }
-
-                                aDateTime.setValue(year, month, day, hour, minute, second, msecond, 0, timezonePart);
+                                GregorianCalendarSystem.getInstance().parseStringForADatetime(serString, offset,
+                                        aDateTime);
                                 datetimeSerde.serialize(aDateTime, out);
                             } else if (serString[0] == SER_NULL_TYPE_TAG)
                                 nullSerde.serialize(ANull.NULL, out);
@@ -144,18 +73,6 @@
                             throw new AlgebricksException(errorMessage);
                         }
                     }
-
-                    private short getValue(byte[] b, int offset, int numberOfDigits) throws AlgebricksException {
-                        value = 0;
-                        for (int i = 0; i < numberOfDigits; i++) {
-                            if ((b[offset] >= '0' && b[offset] <= '9'))
-                                value = (short) (value * 10 + b[offset++] - '0');
-                            else
-                                throw new AlgebricksException(errorMessage);
-
-                        }
-                        return value;
-                    }
                 };
             }
         };