diff --git a/.gitignore b/.gitignore
index c806aca..1108a44 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,4 @@
 .project
 ClusterControllerService
 asterix-app/rttest
+asterix-app/mdtest
\ No newline at end of file
diff --git a/asterix-app/src/test/resources/runtimets/queries/temporal/duration_comps/duration_comps.1.ddl.aql b/asterix-app/src/test/resources/runtimets/queries/temporal/duration_comps/duration_comps.1.ddl.aql
new file mode 100644
index 0000000..cb55dad
--- /dev/null
+++ b/asterix-app/src/test/resources/runtimets/queries/temporal/duration_comps/duration_comps.1.ddl.aql
@@ -0,0 +1,8 @@
+/*
+ * Description      :   Test cases for duration comparison functions
+ * Expected Result  :   Success
+ * Date             :   19 Apr, 2013
+ */
+
+drop dataverse test if exists;
+create dataverse test;
\ No newline at end of file
diff --git a/asterix-app/src/test/resources/runtimets/queries/temporal/duration_comps/duration_comps.2.update.aql b/asterix-app/src/test/resources/runtimets/queries/temporal/duration_comps/duration_comps.2.update.aql
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/asterix-app/src/test/resources/runtimets/queries/temporal/duration_comps/duration_comps.2.update.aql
diff --git a/asterix-app/src/test/resources/runtimets/queries/temporal/duration_comps/duration_comps.3.query.aql b/asterix-app/src/test/resources/runtimets/queries/temporal/duration_comps/duration_comps.3.query.aql
new file mode 100644
index 0000000..77fcc4f
--- /dev/null
+++ b/asterix-app/src/test/resources/runtimets/queries/temporal/duration_comps/duration_comps.3.query.aql
@@ -0,0 +1,11 @@
+use dataverse test;
+
+let $dr1 := duration("-P3D")
+let $dr2 := duration("P1D")
+let $dr3 := duration("P1Y")
+let $dr4 := duration("P13M")
+let $dr5 := duration("PT24H")
+let $dr6 := duration-from-months(months-of-year-month-duration($dr3))
+let $dr7 := duration-from-ms(ms-of-day-time-duration($dr1))
+
+return { "yearMonthGreaterComp" : year-month-duration-greater-than($dr4, $dr3), "dayTimeGreaterComp" : day-time-duration-greater-than($dr2, $dr1), "yearMonthLessComp" : year-month-duration-less-than($dr4, $dr3), "dayTimeLessComp" : day-time-duration-less-than($dr2, $dr1), "equal1": duration-equal($dr2, $dr5), "equal2": duration-equal($dr1, $dr5), "equal3": duration-equal($dr6, $dr3), "equal4": duration-equal($dr7, $dr1) }
\ No newline at end of file
diff --git a/asterix-app/src/test/resources/runtimets/results/temporal/duration_comps/duration_comps.1.adm b/asterix-app/src/test/resources/runtimets/results/temporal/duration_comps/duration_comps.1.adm
new file mode 100644
index 0000000..26b32fc
--- /dev/null
+++ b/asterix-app/src/test/resources/runtimets/results/temporal/duration_comps/duration_comps.1.adm
@@ -0,0 +1 @@
+{ "yearMonthGreaterComp": true, "dayTimeGreaterComp": true, "yearMonthLessComp": false, "dayTimeLessComp": false, "equal1": true, "equal2": false, "equal3": true, "equal4": true }
\ No newline at end of file
diff --git a/asterix-app/src/test/resources/runtimets/testsuite.xml b/asterix-app/src/test/resources/runtimets/testsuite.xml
index 17ec2bb..dd29a7b 100644
--- a/asterix-app/src/test/resources/runtimets/testsuite.xml
+++ b/asterix-app/src/test/resources/runtimets/testsuite.xml
@@ -4205,6 +4205,11 @@
         <output-dir compare="Text">interval</output-dir>
       </compilation-unit>
   	</test-case>
+  	<test-case FilePath="temporal">
+  		<compilation-unit name="duration_comps">
+        <output-dir compare="Text">duration_comps</output-dir>
+      </compilation-unit>
+  	</test-case>
   </test-group>
   <test-group name="leftouterjoin">
     <test-case FilePath="leftouterjoin">
diff --git a/asterix-om/src/main/java/edu/uci/ics/asterix/om/functions/AsterixBuiltinFunctions.java b/asterix-om/src/main/java/edu/uci/ics/asterix/om/functions/AsterixBuiltinFunctions.java
index fa3179a..3cad3be 100644
--- a/asterix-om/src/main/java/edu/uci/ics/asterix/om/functions/AsterixBuiltinFunctions.java
+++ b/asterix-om/src/main/java/edu/uci/ics/asterix/om/functions/AsterixBuiltinFunctions.java
@@ -414,6 +414,24 @@
             "current-date", 0);
     public final static FunctionIdentifier CURRENT_DATETIME = new FunctionIdentifier(FunctionConstants.ASTERIX_NS,
             "current-datetime", 0);
+    public final static FunctionIdentifier DURATION_EQUAL = new FunctionIdentifier(FunctionConstants.ASTERIX_NS,
+            "duration-equal", 2);
+    public final static FunctionIdentifier YEAR_MONTH_DURATION_GREATER_THAN = new FunctionIdentifier(
+            FunctionConstants.ASTERIX_NS, "year-month-duration-greater-than", 2);
+    public final static FunctionIdentifier YEAR_MONTH_DURATION_LESS_THAN = new FunctionIdentifier(
+            FunctionConstants.ASTERIX_NS, "year-month-duration-less-than", 2);
+    public final static FunctionIdentifier DAY_TIME_DURATION_GREATER_THAN = new FunctionIdentifier(
+            FunctionConstants.ASTERIX_NS, "day-time-duration-greater-than", 2);
+    public final static FunctionIdentifier DAY_TIME_DURATION_LESS_THAN = new FunctionIdentifier(
+            FunctionConstants.ASTERIX_NS, "day-time-duration-less-than", 2);
+    public final static FunctionIdentifier DURATION_FROM_MONTHS = new FunctionIdentifier(FunctionConstants.ASTERIX_NS,
+            "duration-from-months", 1);
+    public final static FunctionIdentifier MONTHS_OF_YEAR_MONTH_DURATION = new FunctionIdentifier(
+            FunctionConstants.ASTERIX_NS, "months-of-year-month-duration", 1);
+    public final static FunctionIdentifier DURATION_FROM_MILLISECONDS = new FunctionIdentifier(
+            FunctionConstants.ASTERIX_NS, "duration-from-ms", 1);
+    public final static FunctionIdentifier MILLISECONDS_OF_DAY_TIME_DURATION = new FunctionIdentifier(
+            FunctionConstants.ASTERIX_NS, "ms-of-day-time-duration", 1);
 
     // spatial
     public final static FunctionIdentifier CREATE_POINT = new FunctionIdentifier(FunctionConstants.ASTERIX_NS,
@@ -815,6 +833,15 @@
         add(CURRENT_DATE, ADateTypeComputer.INSTANCE);
         add(CURRENT_TIME, ATimeTypeComputer.INSTANCE);
         add(CURRENT_DATETIME, ADateTimeTypeComputer.INSTANCE);
+        add(DAY_TIME_DURATION_GREATER_THAN, OptionalABooleanTypeComputer.INSTANCE);
+        add(DAY_TIME_DURATION_LESS_THAN, OptionalABooleanTypeComputer.INSTANCE);
+        add(YEAR_MONTH_DURATION_GREATER_THAN, OptionalABooleanTypeComputer.INSTANCE);
+        add(YEAR_MONTH_DURATION_LESS_THAN, OptionalABooleanTypeComputer.INSTANCE);
+        add(DURATION_EQUAL, OptionalABooleanTypeComputer.INSTANCE);
+        add(DURATION_FROM_MONTHS, OptionalADurationTypeComputer.INSTANCE);
+        add(DURATION_FROM_MILLISECONDS, OptionalADurationTypeComputer.INSTANCE);
+        add(MONTHS_OF_YEAR_MONTH_DURATION, OptionalAInt32TypeComputer.INSTANCE);
+        add(MILLISECONDS_OF_DAY_TIME_DURATION, OptionalAInt64TypeComputer.INSTANCE);
 
         // interval constructors
         add(INTERVAL_CONSTRUCTOR_DATE, OptionalAIntervalTypeComputer.INSTANCE);
diff --git a/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/temporal/DayTimeDurationComparatorDescriptor.java b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/temporal/DayTimeDurationComparatorDescriptor.java
new file mode 100644
index 0000000..bb83016
--- /dev/null
+++ b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/temporal/DayTimeDurationComparatorDescriptor.java
@@ -0,0 +1,149 @@
+/*
+ * Copyright 2009-2013 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.
+ */
+package edu.uci.ics.asterix.runtime.evaluators.functions.temporal;
+
+import java.io.DataOutput;
+
+import edu.uci.ics.asterix.dataflow.data.nontagged.serde.ADurationSerializerDeserializer;
+import edu.uci.ics.asterix.formats.nontagged.AqlSerializerDeserializerProvider;
+import edu.uci.ics.asterix.om.base.ABoolean;
+import edu.uci.ics.asterix.om.base.ANull;
+import edu.uci.ics.asterix.om.functions.AsterixBuiltinFunctions;
+import edu.uci.ics.asterix.om.functions.IFunctionDescriptor;
+import edu.uci.ics.asterix.om.functions.IFunctionDescriptorFactory;
+import edu.uci.ics.asterix.om.types.ATypeTag;
+import edu.uci.ics.asterix.om.types.BuiltinType;
+import edu.uci.ics.asterix.om.types.EnumDeserializer;
+import edu.uci.ics.asterix.runtime.evaluators.base.AbstractScalarFunctionDynamicDescriptor;
+import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
+import edu.uci.ics.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
+import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluator;
+import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluatorFactory;
+import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.data.std.api.IDataOutputProvider;
+import edu.uci.ics.hyracks.data.std.util.ArrayBackedValueStorage;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
+
+public class DayTimeDurationComparatorDescriptor extends AbstractScalarFunctionDynamicDescriptor {
+
+    private final static long serialVersionUID = 1L;
+    public final static FunctionIdentifier GREATER_THAN_FID = AsterixBuiltinFunctions.DAY_TIME_DURATION_GREATER_THAN;
+    public final static FunctionIdentifier LESS_THAN_FID = AsterixBuiltinFunctions.DAY_TIME_DURATION_LESS_THAN;
+
+    // allowed input types
+    private final static byte SER_NULL_TYPE_TAG = ATypeTag.NULL.serialize();
+    private final static byte SER_DURATION_TYPE_TAG = ATypeTag.DURATION.serialize();
+
+    private final boolean isGreaterThan;
+
+    private DayTimeDurationComparatorDescriptor(boolean isGreaterThan) {
+        this.isGreaterThan = isGreaterThan;
+    }
+
+    public final static IFunctionDescriptorFactory GREATER_THAN_FACTORY = new IFunctionDescriptorFactory() {
+
+        @Override
+        public IFunctionDescriptor createFunctionDescriptor() {
+            return new DayTimeDurationComparatorDescriptor(true);
+        }
+    };
+
+    public final static IFunctionDescriptorFactory LESS_THAN_FACTORY = new IFunctionDescriptorFactory() {
+
+        @Override
+        public IFunctionDescriptor createFunctionDescriptor() {
+            return new DayTimeDurationComparatorDescriptor(false);
+        }
+    };
+
+    @Override
+    public ICopyEvaluatorFactory createEvaluatorFactory(final ICopyEvaluatorFactory[] args) throws AlgebricksException {
+        return new ICopyEvaluatorFactory() {
+
+            private static final long serialVersionUID = 1L;
+
+            @Override
+            public ICopyEvaluator createEvaluator(final IDataOutputProvider output) throws AlgebricksException {
+                return new ICopyEvaluator() {
+
+                    private DataOutput out = output.getDataOutput();
+                    private ArrayBackedValueStorage argOut0 = new ArrayBackedValueStorage();
+                    private ArrayBackedValueStorage argOut1 = new ArrayBackedValueStorage();
+                    private ICopyEvaluator eval0 = args[0].createEvaluator(argOut0);
+                    private ICopyEvaluator eval1 = args[1].createEvaluator(argOut1);
+
+                    // possible output types
+                    @SuppressWarnings("unchecked")
+                    private ISerializerDeserializer<ANull> nullSerde = AqlSerializerDeserializerProvider.INSTANCE
+                            .getSerializerDeserializer(BuiltinType.ANULL);
+                    @SuppressWarnings("unchecked")
+                    private ISerializerDeserializer<ABoolean> boolSerde = AqlSerializerDeserializerProvider.INSTANCE
+                            .getSerializerDeserializer(BuiltinType.ABOOLEAN);
+
+                    @Override
+                    public void evaluate(IFrameTupleReference tuple) throws AlgebricksException {
+                        argOut0.reset();
+                        eval0.evaluate(tuple);
+                        argOut1.reset();
+                        eval1.evaluate(tuple);
+
+                        try {
+                            if (argOut0.getByteArray()[0] == SER_NULL_TYPE_TAG
+                                    || argOut1.getByteArray()[0] == SER_NULL_TYPE_TAG) {
+                                nullSerde.serialize(ANull.NULL, out);
+                                return;
+                            }
+
+                            if (argOut0.getByteArray()[0] != SER_DURATION_TYPE_TAG
+                                    || argOut1.getByteArray()[0] != SER_DURATION_TYPE_TAG) {
+                                throw new AlgebricksException(getIdentifier().getName()
+                                        + ": expects type NULL/DURATION, NULL/DURATION but got "
+                                        + EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(argOut0.getByteArray()[0])
+                                        + " and "
+                                        + EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(argOut1.getByteArray()[0]));
+                            }
+
+                            if ((ADurationSerializerDeserializer.getYearMonth(argOut0.getByteArray(), 1) != 0)
+                                    || (ADurationSerializerDeserializer.getYearMonth(argOut1.getByteArray(), 1) != 0)) {
+                                throw new AlgebricksException(getIdentifier().getName()
+                                        + ": only year-month durations are allowed.");
+                            }
+
+                            if (ADurationSerializerDeserializer.getDayTime(argOut0.getByteArray(), 1) > ADurationSerializerDeserializer
+                                    .getDayTime(argOut1.getByteArray(), 1)) {
+                                boolSerde.serialize(isGreaterThan ? ABoolean.TRUE : ABoolean.FALSE, out);
+                            } else {
+                                boolSerde.serialize(isGreaterThan ? ABoolean.FALSE : ABoolean.TRUE, out);
+                            }
+
+                        } catch (HyracksDataException hex) {
+                            throw new AlgebricksException(hex);
+                        }
+                    }
+                };
+            }
+        };
+    }
+
+    /* (non-Javadoc)
+     * @see edu.uci.ics.asterix.om.functions.AbstractFunctionDescriptor#getIdentifier()
+     */
+    @Override
+    public FunctionIdentifier getIdentifier() {
+        return isGreaterThan ? GREATER_THAN_FID : LESS_THAN_FID;
+    }
+
+}
diff --git a/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/temporal/DurationEqualDescriptor.java b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/temporal/DurationEqualDescriptor.java
new file mode 100644
index 0000000..fceb144
--- /dev/null
+++ b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/temporal/DurationEqualDescriptor.java
@@ -0,0 +1,130 @@
+/*
+ * Copyright 2009-2013 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.
+ */
+package edu.uci.ics.asterix.runtime.evaluators.functions.temporal;
+
+import java.io.DataOutput;
+
+import edu.uci.ics.asterix.dataflow.data.nontagged.serde.ADurationSerializerDeserializer;
+import edu.uci.ics.asterix.formats.nontagged.AqlSerializerDeserializerProvider;
+import edu.uci.ics.asterix.om.base.ABoolean;
+import edu.uci.ics.asterix.om.base.ANull;
+import edu.uci.ics.asterix.om.functions.AsterixBuiltinFunctions;
+import edu.uci.ics.asterix.om.functions.IFunctionDescriptor;
+import edu.uci.ics.asterix.om.functions.IFunctionDescriptorFactory;
+import edu.uci.ics.asterix.om.types.ATypeTag;
+import edu.uci.ics.asterix.om.types.BuiltinType;
+import edu.uci.ics.asterix.om.types.EnumDeserializer;
+import edu.uci.ics.asterix.runtime.evaluators.base.AbstractScalarFunctionDynamicDescriptor;
+import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
+import edu.uci.ics.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
+import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluator;
+import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluatorFactory;
+import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.data.std.api.IDataOutputProvider;
+import edu.uci.ics.hyracks.data.std.util.ArrayBackedValueStorage;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
+
+public class DurationEqualDescriptor extends AbstractScalarFunctionDynamicDescriptor {
+
+    private final static long serialVersionUID = 1L;
+    public final static FunctionIdentifier FID = AsterixBuiltinFunctions.DURATION_EQUAL;
+
+    // allowed input types
+    private final static byte SER_NULL_TYPE_TAG = ATypeTag.NULL.serialize();
+    private final static byte SER_DURATION_TYPE_TAG = ATypeTag.DURATION.serialize();
+
+    public final static IFunctionDescriptorFactory FACTORY = new IFunctionDescriptorFactory() {
+
+        @Override
+        public IFunctionDescriptor createFunctionDescriptor() {
+            return new DurationEqualDescriptor();
+        }
+    };
+
+    @Override
+    public ICopyEvaluatorFactory createEvaluatorFactory(final ICopyEvaluatorFactory[] args) throws AlgebricksException {
+        return new ICopyEvaluatorFactory() {
+
+            private static final long serialVersionUID = 1L;
+
+            @Override
+            public ICopyEvaluator createEvaluator(final IDataOutputProvider output) throws AlgebricksException {
+                return new ICopyEvaluator() {
+
+                    private DataOutput out = output.getDataOutput();
+                    private ArrayBackedValueStorage argOut0 = new ArrayBackedValueStorage();
+                    private ArrayBackedValueStorage argOut1 = new ArrayBackedValueStorage();
+                    private ICopyEvaluator eval0 = args[0].createEvaluator(argOut0);
+                    private ICopyEvaluator eval1 = args[1].createEvaluator(argOut1);
+
+                    // possible output types
+                    @SuppressWarnings("unchecked")
+                    private ISerializerDeserializer<ANull> nullSerde = AqlSerializerDeserializerProvider.INSTANCE
+                            .getSerializerDeserializer(BuiltinType.ANULL);
+                    @SuppressWarnings("unchecked")
+                    private ISerializerDeserializer<ABoolean> boolSerde = AqlSerializerDeserializerProvider.INSTANCE
+                            .getSerializerDeserializer(BuiltinType.ABOOLEAN);
+
+                    @Override
+                    public void evaluate(IFrameTupleReference tuple) throws AlgebricksException {
+                        argOut0.reset();
+                        eval0.evaluate(tuple);
+                        argOut1.reset();
+                        eval1.evaluate(tuple);
+
+                        try {
+                            if (argOut0.getByteArray()[0] == SER_NULL_TYPE_TAG
+                                    || argOut1.getByteArray()[0] == SER_NULL_TYPE_TAG) {
+                                nullSerde.serialize(ANull.NULL, out);
+                                return;
+                            }
+
+                            if (argOut0.getByteArray()[0] != SER_DURATION_TYPE_TAG
+                                    || argOut1.getByteArray()[0] != SER_DURATION_TYPE_TAG) {
+                                throw new AlgebricksException(FID.getName()
+                                        + ": expects type NULL/DURATION, NULL/DURATION but got "
+                                        + EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(argOut0.getByteArray()[0])
+                                        + " and "
+                                        + EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(argOut1.getByteArray()[0]));
+                            }
+
+                            if ((ADurationSerializerDeserializer.getDayTime(argOut0.getByteArray(), 1) == ADurationSerializerDeserializer
+                                    .getDayTime(argOut1.getByteArray(), 1))
+                                    && (ADurationSerializerDeserializer.getYearMonth(argOut0.getByteArray(), 1) == ADurationSerializerDeserializer
+                                            .getYearMonth(argOut1.getByteArray(), 1))) {
+                                boolSerde.serialize(ABoolean.TRUE, out);
+                            } else {
+                                boolSerde.serialize(ABoolean.FALSE, out);
+                            }
+
+                        } catch (HyracksDataException hex) {
+                            throw new AlgebricksException(hex);
+                        }
+                    }
+                };
+            }
+        };
+    }
+
+    /* (non-Javadoc)
+     * @see edu.uci.ics.asterix.om.functions.AbstractFunctionDescriptor#getIdentifier()
+     */
+    @Override
+    public FunctionIdentifier getIdentifier() {
+        return FID;
+    }
+
+}
diff --git a/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/temporal/DurationFromMillisecondsDescriptor.java b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/temporal/DurationFromMillisecondsDescriptor.java
new file mode 100644
index 0000000..267f4a7
--- /dev/null
+++ b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/temporal/DurationFromMillisecondsDescriptor.java
@@ -0,0 +1,133 @@
+/*
+ * Copyright 2009-2013 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.
+ */
+package edu.uci.ics.asterix.runtime.evaluators.functions.temporal;
+
+import java.io.DataOutput;
+
+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.dataflow.data.nontagged.serde.AInt8SerializerDeserializer;
+import edu.uci.ics.asterix.formats.nontagged.AqlSerializerDeserializerProvider;
+import edu.uci.ics.asterix.om.base.ADuration;
+import edu.uci.ics.asterix.om.base.AMutableDuration;
+import edu.uci.ics.asterix.om.base.ANull;
+import edu.uci.ics.asterix.om.functions.AsterixBuiltinFunctions;
+import edu.uci.ics.asterix.om.functions.IFunctionDescriptor;
+import edu.uci.ics.asterix.om.functions.IFunctionDescriptorFactory;
+import edu.uci.ics.asterix.om.types.ATypeTag;
+import edu.uci.ics.asterix.om.types.BuiltinType;
+import edu.uci.ics.asterix.om.types.EnumDeserializer;
+import edu.uci.ics.asterix.runtime.evaluators.base.AbstractScalarFunctionDynamicDescriptor;
+import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
+import edu.uci.ics.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
+import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluator;
+import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluatorFactory;
+import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.data.std.api.IDataOutputProvider;
+import edu.uci.ics.hyracks.data.std.util.ArrayBackedValueStorage;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
+
+public class DurationFromMillisecondsDescriptor extends AbstractScalarFunctionDynamicDescriptor {
+
+    private final static long serialVersionUID = 1L;
+    public final static FunctionIdentifier FID = AsterixBuiltinFunctions.DURATION_FROM_MILLISECONDS;
+
+    // allowed input types
+    private final static byte SER_NULL_TYPE_TAG = ATypeTag.NULL.serialize();
+    private final static byte SER_INT8_TYPE_TAG = ATypeTag.INT8.serialize();
+    private final static byte SER_INT16_TYPE_TAG = ATypeTag.INT16.serialize();
+    private final static byte SER_INT32_TYPE_TAG = ATypeTag.INT32.serialize();
+    private final static byte SER_INT64_TYPE_TAG = ATypeTag.INT64.serialize();
+
+    public final static IFunctionDescriptorFactory FACTORY = new IFunctionDescriptorFactory() {
+
+        @Override
+        public IFunctionDescriptor createFunctionDescriptor() {
+            return new DurationFromMillisecondsDescriptor();
+        }
+    };
+
+    @Override
+    public ICopyEvaluatorFactory createEvaluatorFactory(final ICopyEvaluatorFactory[] args) throws AlgebricksException {
+        return new ICopyEvaluatorFactory() {
+
+            private static final long serialVersionUID = 1L;
+
+            @Override
+            public ICopyEvaluator createEvaluator(final IDataOutputProvider output) throws AlgebricksException {
+                return new ICopyEvaluator() {
+
+                    private DataOutput out = output.getDataOutput();
+                    private ArrayBackedValueStorage argOut0 = new ArrayBackedValueStorage();
+                    private ICopyEvaluator eval0 = args[0].createEvaluator(argOut0);
+
+                    // possible output types
+                    @SuppressWarnings("unchecked")
+                    private ISerializerDeserializer<ANull> nullSerde = AqlSerializerDeserializerProvider.INSTANCE
+                            .getSerializerDeserializer(BuiltinType.ANULL);
+                    @SuppressWarnings("unchecked")
+                    private ISerializerDeserializer<ADuration> durationSerde = AqlSerializerDeserializerProvider.INSTANCE
+                            .getSerializerDeserializer(BuiltinType.ADURATION);
+
+                    AMutableDuration aDuration = new AMutableDuration(0, 0);
+
+                    @Override
+                    public void evaluate(IFrameTupleReference tuple) throws AlgebricksException {
+                        argOut0.reset();
+                        eval0.evaluate(tuple);
+
+                        try {
+                            if (argOut0.getByteArray()[0] == SER_NULL_TYPE_TAG) {
+                                nullSerde.serialize(ANull.NULL, out);
+                                return;
+                            }
+
+                            if (argOut0.getByteArray()[0] == SER_INT8_TYPE_TAG) {
+                                aDuration.setValue(0, AInt8SerializerDeserializer.getByte(argOut0.getByteArray(), 1));
+                            } else if (argOut0.getByteArray()[0] == SER_INT16_TYPE_TAG) {
+                                aDuration.setValue(0, AInt16SerializerDeserializer.getShort(argOut0.getByteArray(), 1));
+                            } else if (argOut0.getByteArray()[0] == SER_INT32_TYPE_TAG) {
+                                aDuration.setValue(0, AInt32SerializerDeserializer.getInt(argOut0.getByteArray(), 1));
+                            } else if (argOut0.getByteArray()[0] == SER_INT64_TYPE_TAG) {
+                                aDuration.setValue(0, AInt64SerializerDeserializer.getLong(argOut0.getByteArray(), 1));
+                            } else {
+                                throw new AlgebricksException(FID.getName()
+                                        + ": expects NULL/INT8/INT16/INT32/INT64, but got "
+                                        + EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(argOut0.getByteArray()[0]));
+                            }
+
+                            durationSerde.serialize(aDuration, out);
+
+                        } catch (HyracksDataException hex) {
+                            throw new AlgebricksException(hex);
+                        }
+                    }
+                };
+            }
+
+        };
+    }
+
+    /* (non-Javadoc)
+     * @see edu.uci.ics.asterix.om.functions.AbstractFunctionDescriptor#getIdentifier()
+     */
+    @Override
+    public FunctionIdentifier getIdentifier() {
+        return FID;
+    }
+
+}
diff --git a/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/temporal/DurationFromMonthsDescriptor.java b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/temporal/DurationFromMonthsDescriptor.java
new file mode 100644
index 0000000..f8b7a3e
--- /dev/null
+++ b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/temporal/DurationFromMonthsDescriptor.java
@@ -0,0 +1,129 @@
+/*
+ * Copyright 2009-2013 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.
+ */
+package edu.uci.ics.asterix.runtime.evaluators.functions.temporal;
+
+import java.io.DataOutput;
+
+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.AInt8SerializerDeserializer;
+import edu.uci.ics.asterix.formats.nontagged.AqlSerializerDeserializerProvider;
+import edu.uci.ics.asterix.om.base.ADuration;
+import edu.uci.ics.asterix.om.base.AMutableDuration;
+import edu.uci.ics.asterix.om.base.ANull;
+import edu.uci.ics.asterix.om.functions.AsterixBuiltinFunctions;
+import edu.uci.ics.asterix.om.functions.IFunctionDescriptor;
+import edu.uci.ics.asterix.om.functions.IFunctionDescriptorFactory;
+import edu.uci.ics.asterix.om.types.ATypeTag;
+import edu.uci.ics.asterix.om.types.BuiltinType;
+import edu.uci.ics.asterix.om.types.EnumDeserializer;
+import edu.uci.ics.asterix.runtime.evaluators.base.AbstractScalarFunctionDynamicDescriptor;
+import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
+import edu.uci.ics.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
+import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluator;
+import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluatorFactory;
+import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.data.std.api.IDataOutputProvider;
+import edu.uci.ics.hyracks.data.std.util.ArrayBackedValueStorage;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
+
+public class DurationFromMonthsDescriptor extends AbstractScalarFunctionDynamicDescriptor {
+
+    private final static long serialVersionUID = 1L;
+    public final static FunctionIdentifier FID = AsterixBuiltinFunctions.DURATION_FROM_MONTHS;
+
+    // allowed input types
+    private final static byte SER_NULL_TYPE_TAG = ATypeTag.NULL.serialize();
+    private final static byte SER_INT8_TYPE_TAG = ATypeTag.INT8.serialize();
+    private final static byte SER_INT16_TYPE_TAG = ATypeTag.INT16.serialize();
+    private final static byte SER_INT32_TYPE_TAG = ATypeTag.INT32.serialize();
+
+    public final static IFunctionDescriptorFactory FACTORY = new IFunctionDescriptorFactory() {
+
+        @Override
+        public IFunctionDescriptor createFunctionDescriptor() {
+            return new DurationFromMonthsDescriptor();
+        }
+    };
+
+    @Override
+    public ICopyEvaluatorFactory createEvaluatorFactory(final ICopyEvaluatorFactory[] args) throws AlgebricksException {
+        return new ICopyEvaluatorFactory() {
+
+            private static final long serialVersionUID = 1L;
+
+            @Override
+            public ICopyEvaluator createEvaluator(final IDataOutputProvider output) throws AlgebricksException {
+                return new ICopyEvaluator() {
+
+                    private DataOutput out = output.getDataOutput();
+                    private ArrayBackedValueStorage argOut0 = new ArrayBackedValueStorage();
+                    private ICopyEvaluator eval0 = args[0].createEvaluator(argOut0);
+
+                    // possible output types
+                    @SuppressWarnings("unchecked")
+                    private ISerializerDeserializer<ANull> nullSerde = AqlSerializerDeserializerProvider.INSTANCE
+                            .getSerializerDeserializer(BuiltinType.ANULL);
+                    @SuppressWarnings("unchecked")
+                    private ISerializerDeserializer<ADuration> durationSerde = AqlSerializerDeserializerProvider.INSTANCE
+                            .getSerializerDeserializer(BuiltinType.ADURATION);
+
+                    AMutableDuration aDuration = new AMutableDuration(0, 0);
+
+                    @Override
+                    public void evaluate(IFrameTupleReference tuple) throws AlgebricksException {
+                        argOut0.reset();
+                        eval0.evaluate(tuple);
+
+                        try {
+                            if (argOut0.getByteArray()[0] == SER_NULL_TYPE_TAG) {
+                                nullSerde.serialize(ANull.NULL, out);
+                                return;
+                            }
+
+                            if (argOut0.getByteArray()[0] == SER_INT8_TYPE_TAG) {
+                                aDuration.setValue(AInt8SerializerDeserializer.getByte(argOut0.getByteArray(), 1), 0);
+                            } else if (argOut0.getByteArray()[0] == SER_INT16_TYPE_TAG) {
+                                aDuration.setValue(AInt16SerializerDeserializer.getShort(argOut0.getByteArray(), 1), 0);
+                            } else if (argOut0.getByteArray()[0] == SER_INT32_TYPE_TAG) {
+                                aDuration.setValue(AInt32SerializerDeserializer.getInt(argOut0.getByteArray(), 1), 0);
+                            } else {
+                                throw new AlgebricksException(FID.getName()
+                                        + ": expects NULL/INT8/INT16/INT32, but got "
+                                        + EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(argOut0.getByteArray()[0]));
+                            }
+
+                            durationSerde.serialize(aDuration, out);
+
+                        } catch (HyracksDataException hex) {
+                            throw new AlgebricksException(hex);
+                        }
+                    }
+                };
+            }
+
+        };
+    }
+
+    /* (non-Javadoc)
+     * @see edu.uci.ics.asterix.om.functions.AbstractFunctionDescriptor#getIdentifier()
+     */
+    @Override
+    public FunctionIdentifier getIdentifier() {
+        return FID;
+    }
+
+}
diff --git a/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/temporal/MillisecondsOfDayTimeDurationDescriptor.java b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/temporal/MillisecondsOfDayTimeDurationDescriptor.java
new file mode 100644
index 0000000..97fa94a
--- /dev/null
+++ b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/temporal/MillisecondsOfDayTimeDurationDescriptor.java
@@ -0,0 +1,120 @@
+/*
+ * Copyright 2009-2013 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.
+ */
+package edu.uci.ics.asterix.runtime.evaluators.functions.temporal;
+
+import java.io.DataOutput;
+
+import edu.uci.ics.asterix.dataflow.data.nontagged.serde.ADurationSerializerDeserializer;
+import edu.uci.ics.asterix.formats.nontagged.AqlSerializerDeserializerProvider;
+import edu.uci.ics.asterix.om.base.AInt64;
+import edu.uci.ics.asterix.om.base.AMutableInt64;
+import edu.uci.ics.asterix.om.base.ANull;
+import edu.uci.ics.asterix.om.functions.AsterixBuiltinFunctions;
+import edu.uci.ics.asterix.om.functions.IFunctionDescriptor;
+import edu.uci.ics.asterix.om.functions.IFunctionDescriptorFactory;
+import edu.uci.ics.asterix.om.types.ATypeTag;
+import edu.uci.ics.asterix.om.types.BuiltinType;
+import edu.uci.ics.asterix.om.types.EnumDeserializer;
+import edu.uci.ics.asterix.runtime.evaluators.base.AbstractScalarFunctionDynamicDescriptor;
+import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
+import edu.uci.ics.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
+import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluator;
+import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluatorFactory;
+import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.data.std.api.IDataOutputProvider;
+import edu.uci.ics.hyracks.data.std.util.ArrayBackedValueStorage;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
+
+public class MillisecondsOfDayTimeDurationDescriptor extends AbstractScalarFunctionDynamicDescriptor {
+
+    private final static long serialVersionUID = 1L;
+    public final static FunctionIdentifier FID = AsterixBuiltinFunctions.MILLISECONDS_OF_DAY_TIME_DURATION;
+
+    // allowed input types
+    private final static byte SER_NULL_TYPE_TAG = ATypeTag.NULL.serialize();
+    private final static byte SER_DURATION_TYPE_TAG = ATypeTag.DURATION.serialize();
+
+    public final static IFunctionDescriptorFactory FACTORY = new IFunctionDescriptorFactory() {
+
+        @Override
+        public IFunctionDescriptor createFunctionDescriptor() {
+            return new MillisecondsOfDayTimeDurationDescriptor();
+        }
+    };
+
+    @Override
+    public ICopyEvaluatorFactory createEvaluatorFactory(final ICopyEvaluatorFactory[] args) throws AlgebricksException {
+        return new ICopyEvaluatorFactory() {
+
+            private static final long serialVersionUID = 1L;
+
+            @Override
+            public ICopyEvaluator createEvaluator(final IDataOutputProvider output) throws AlgebricksException {
+                return new ICopyEvaluator() {
+
+                    private DataOutput out = output.getDataOutput();
+                    private ArrayBackedValueStorage argOut0 = new ArrayBackedValueStorage();
+                    private ICopyEvaluator eval0 = args[0].createEvaluator(argOut0);
+
+                    // possible output types
+                    @SuppressWarnings("unchecked")
+                    private ISerializerDeserializer<ANull> nullSerde = AqlSerializerDeserializerProvider.INSTANCE
+                            .getSerializerDeserializer(BuiltinType.ANULL);
+                    @SuppressWarnings("unchecked")
+                    private ISerializerDeserializer<AInt64> int64Serde = AqlSerializerDeserializerProvider.INSTANCE
+                            .getSerializerDeserializer(BuiltinType.AINT64);
+
+                    AMutableInt64 aInt64 = new AMutableInt64(0);
+
+                    @Override
+                    public void evaluate(IFrameTupleReference tuple) throws AlgebricksException {
+                        argOut0.reset();
+                        eval0.evaluate(tuple);
+
+                        try {
+                            if (argOut0.getByteArray()[0] == SER_NULL_TYPE_TAG) {
+                                nullSerde.serialize(ANull.NULL, out);
+                                return;
+                            }
+
+                            if (argOut0.getByteArray()[0] != SER_DURATION_TYPE_TAG) {
+                                throw new AlgebricksException(FID.getName() + ": expects NULL/DURATION, but got "
+                                        + EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(argOut0.getByteArray()[0]));
+                            }
+
+                            aInt64.setValue(ADurationSerializerDeserializer.getDayTime(argOut0.getByteArray(), 1));
+
+                            int64Serde.serialize(aInt64, out);
+
+                        } catch (HyracksDataException hex) {
+                            throw new AlgebricksException(hex);
+                        }
+                    }
+                };
+            }
+
+        };
+    }
+
+    /* (non-Javadoc)
+     * @see edu.uci.ics.asterix.om.functions.AbstractFunctionDescriptor#getIdentifier()
+     */
+    @Override
+    public FunctionIdentifier getIdentifier() {
+        return FID;
+    }
+
+}
diff --git a/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/temporal/MonthsOfYearMonthDurationDescriptor.java b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/temporal/MonthsOfYearMonthDurationDescriptor.java
new file mode 100644
index 0000000..55173a5
--- /dev/null
+++ b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/temporal/MonthsOfYearMonthDurationDescriptor.java
@@ -0,0 +1,120 @@
+/*
+ * Copyright 2009-2013 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.
+ */
+package edu.uci.ics.asterix.runtime.evaluators.functions.temporal;
+
+import java.io.DataOutput;
+
+import edu.uci.ics.asterix.dataflow.data.nontagged.serde.ADurationSerializerDeserializer;
+import edu.uci.ics.asterix.formats.nontagged.AqlSerializerDeserializerProvider;
+import edu.uci.ics.asterix.om.base.AInt32;
+import edu.uci.ics.asterix.om.base.AMutableInt32;
+import edu.uci.ics.asterix.om.base.ANull;
+import edu.uci.ics.asterix.om.functions.AsterixBuiltinFunctions;
+import edu.uci.ics.asterix.om.functions.IFunctionDescriptor;
+import edu.uci.ics.asterix.om.functions.IFunctionDescriptorFactory;
+import edu.uci.ics.asterix.om.types.ATypeTag;
+import edu.uci.ics.asterix.om.types.BuiltinType;
+import edu.uci.ics.asterix.om.types.EnumDeserializer;
+import edu.uci.ics.asterix.runtime.evaluators.base.AbstractScalarFunctionDynamicDescriptor;
+import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
+import edu.uci.ics.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
+import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluator;
+import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluatorFactory;
+import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.data.std.api.IDataOutputProvider;
+import edu.uci.ics.hyracks.data.std.util.ArrayBackedValueStorage;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
+
+public class MonthsOfYearMonthDurationDescriptor extends AbstractScalarFunctionDynamicDescriptor {
+
+    private final static long serialVersionUID = 1L;
+    public final static FunctionIdentifier FID = AsterixBuiltinFunctions.MONTHS_OF_YEAR_MONTH_DURATION;
+
+    // allowed input types
+    private final static byte SER_NULL_TYPE_TAG = ATypeTag.NULL.serialize();
+    private final static byte SER_DURATION_TYPE_TAG = ATypeTag.DURATION.serialize();
+
+    public final static IFunctionDescriptorFactory FACTORY = new IFunctionDescriptorFactory() {
+
+        @Override
+        public IFunctionDescriptor createFunctionDescriptor() {
+            return new MonthsOfYearMonthDurationDescriptor();
+        }
+    };
+
+    @Override
+    public ICopyEvaluatorFactory createEvaluatorFactory(final ICopyEvaluatorFactory[] args) throws AlgebricksException {
+        return new ICopyEvaluatorFactory() {
+
+            private static final long serialVersionUID = 1L;
+
+            @Override
+            public ICopyEvaluator createEvaluator(final IDataOutputProvider output) throws AlgebricksException {
+                return new ICopyEvaluator() {
+
+                    private DataOutput out = output.getDataOutput();
+                    private ArrayBackedValueStorage argOut0 = new ArrayBackedValueStorage();
+                    private ICopyEvaluator eval0 = args[0].createEvaluator(argOut0);
+
+                    // possible output types
+                    @SuppressWarnings("unchecked")
+                    private ISerializerDeserializer<ANull> nullSerde = AqlSerializerDeserializerProvider.INSTANCE
+                            .getSerializerDeserializer(BuiltinType.ANULL);
+                    @SuppressWarnings("unchecked")
+                    private ISerializerDeserializer<AInt32> int32Serde = AqlSerializerDeserializerProvider.INSTANCE
+                            .getSerializerDeserializer(BuiltinType.AINT32);
+
+                    AMutableInt32 aInt32 = new AMutableInt32(0);
+
+                    @Override
+                    public void evaluate(IFrameTupleReference tuple) throws AlgebricksException {
+                        argOut0.reset();
+                        eval0.evaluate(tuple);
+
+                        try {
+                            if (argOut0.getByteArray()[0] == SER_NULL_TYPE_TAG) {
+                                nullSerde.serialize(ANull.NULL, out);
+                                return;
+                            }
+
+                            if (argOut0.getByteArray()[0] != SER_DURATION_TYPE_TAG) {
+                                throw new AlgebricksException(FID.getName() + ": expects NULL/DURATION, but got "
+                                        + EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(argOut0.getByteArray()[0]));
+                            }
+
+                            aInt32.setValue(ADurationSerializerDeserializer.getYearMonth(argOut0.getByteArray(), 1));
+
+                            int32Serde.serialize(aInt32, out);
+
+                        } catch (HyracksDataException hex) {
+                            throw new AlgebricksException(hex);
+                        }
+                    }
+                };
+            }
+
+        };
+    }
+
+    /* (non-Javadoc)
+     * @see edu.uci.ics.asterix.om.functions.AbstractFunctionDescriptor#getIdentifier()
+     */
+    @Override
+    public FunctionIdentifier getIdentifier() {
+        return FID;
+    }
+
+}
diff --git a/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/temporal/YearMonthDurationComparatorDecriptor.java b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/temporal/YearMonthDurationComparatorDecriptor.java
new file mode 100644
index 0000000..22ab96c
--- /dev/null
+++ b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/temporal/YearMonthDurationComparatorDecriptor.java
@@ -0,0 +1,149 @@
+/*
+ * Copyright 2009-2013 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.
+ */
+package edu.uci.ics.asterix.runtime.evaluators.functions.temporal;
+
+import java.io.DataOutput;
+
+import edu.uci.ics.asterix.dataflow.data.nontagged.serde.ADurationSerializerDeserializer;
+import edu.uci.ics.asterix.formats.nontagged.AqlSerializerDeserializerProvider;
+import edu.uci.ics.asterix.om.base.ABoolean;
+import edu.uci.ics.asterix.om.base.ANull;
+import edu.uci.ics.asterix.om.functions.AsterixBuiltinFunctions;
+import edu.uci.ics.asterix.om.functions.IFunctionDescriptor;
+import edu.uci.ics.asterix.om.functions.IFunctionDescriptorFactory;
+import edu.uci.ics.asterix.om.types.ATypeTag;
+import edu.uci.ics.asterix.om.types.BuiltinType;
+import edu.uci.ics.asterix.om.types.EnumDeserializer;
+import edu.uci.ics.asterix.runtime.evaluators.base.AbstractScalarFunctionDynamicDescriptor;
+import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
+import edu.uci.ics.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
+import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluator;
+import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluatorFactory;
+import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.data.std.api.IDataOutputProvider;
+import edu.uci.ics.hyracks.data.std.util.ArrayBackedValueStorage;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
+
+public class YearMonthDurationComparatorDecriptor extends AbstractScalarFunctionDynamicDescriptor {
+
+    private final static long serialVersionUID = 1L;
+    public final static FunctionIdentifier GREATER_THAN_FID = AsterixBuiltinFunctions.YEAR_MONTH_DURATION_GREATER_THAN;
+    public final static FunctionIdentifier LESS_THAN_FID = AsterixBuiltinFunctions.YEAR_MONTH_DURATION_LESS_THAN;
+
+    // allowed input types
+    private final static byte SER_NULL_TYPE_TAG = ATypeTag.NULL.serialize();
+    private final static byte SER_DURATION_TYPE_TAG = ATypeTag.DURATION.serialize();
+    
+    private final boolean isGreaterThan;
+
+    private YearMonthDurationComparatorDecriptor(boolean isGreaterThan) {
+        this.isGreaterThan = isGreaterThan;
+    }
+
+    public final static IFunctionDescriptorFactory GREATER_THAN_FACTORY = new IFunctionDescriptorFactory() {
+
+        @Override
+        public IFunctionDescriptor createFunctionDescriptor() {
+            return new YearMonthDurationComparatorDecriptor(true);
+        }
+    };
+
+    public final static IFunctionDescriptorFactory LESS_THAN_FACTORY = new IFunctionDescriptorFactory() {
+
+        @Override
+        public IFunctionDescriptor createFunctionDescriptor() {
+            return new YearMonthDurationComparatorDecriptor(false);
+        }
+    };
+
+    @Override
+    public ICopyEvaluatorFactory createEvaluatorFactory(final ICopyEvaluatorFactory[] args) throws AlgebricksException {
+        return new ICopyEvaluatorFactory() {
+
+            private static final long serialVersionUID = 1L;
+
+            @Override
+            public ICopyEvaluator createEvaluator(final IDataOutputProvider output) throws AlgebricksException {
+                return new ICopyEvaluator() {
+
+                    private DataOutput out = output.getDataOutput();
+                    private ArrayBackedValueStorage argOut0 = new ArrayBackedValueStorage();
+                    private ArrayBackedValueStorage argOut1 = new ArrayBackedValueStorage();
+                    private ICopyEvaluator eval0 = args[0].createEvaluator(argOut0);
+                    private ICopyEvaluator eval1 = args[1].createEvaluator(argOut1);
+
+                    // possible output types
+                    @SuppressWarnings("unchecked")
+                    private ISerializerDeserializer<ANull> nullSerde = AqlSerializerDeserializerProvider.INSTANCE
+                            .getSerializerDeserializer(BuiltinType.ANULL);
+                    @SuppressWarnings("unchecked")
+                    private ISerializerDeserializer<ABoolean> boolSerde = AqlSerializerDeserializerProvider.INSTANCE
+                            .getSerializerDeserializer(BuiltinType.ABOOLEAN);
+
+                    @Override
+                    public void evaluate(IFrameTupleReference tuple) throws AlgebricksException {
+                        argOut0.reset();
+                        eval0.evaluate(tuple);
+                        argOut1.reset();
+                        eval1.evaluate(tuple);
+
+                        try {
+                            if (argOut0.getByteArray()[0] == SER_NULL_TYPE_TAG
+                                    || argOut1.getByteArray()[0] == SER_NULL_TYPE_TAG) {
+                                nullSerde.serialize(ANull.NULL, out);
+                                return;
+                            }
+
+                            if (argOut0.getByteArray()[0] != SER_DURATION_TYPE_TAG
+                                    || argOut1.getByteArray()[0] != SER_DURATION_TYPE_TAG) {
+                                throw new AlgebricksException(getIdentifier().getName()
+                                        + ": expects type NULL/DURATION, NULL/DURATION but got "
+                                        + EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(argOut0.getByteArray()[0])
+                                        + " and "
+                                        + EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(argOut1.getByteArray()[0]));
+                            }
+
+                            if ((ADurationSerializerDeserializer.getDayTime(argOut0.getByteArray(), 1) != 0)
+                                    || (ADurationSerializerDeserializer.getDayTime(argOut1.getByteArray(), 1) != 0)) {
+                                throw new AlgebricksException(getIdentifier().getName()
+                                        + ": only year-month durations are allowed.");
+                            }
+
+                            if (ADurationSerializerDeserializer.getYearMonth(argOut0.getByteArray(), 1) > ADurationSerializerDeserializer
+                                    .getYearMonth(argOut1.getByteArray(), 1)) {
+                                boolSerde.serialize(isGreaterThan ? ABoolean.TRUE : ABoolean.FALSE, out);
+                            } else {
+                                boolSerde.serialize(isGreaterThan ? ABoolean.FALSE : ABoolean.TRUE, out);
+                            }
+
+                        } catch (HyracksDataException hex) {
+                            throw new AlgebricksException(hex);
+                        }
+                    }
+                };
+            }
+        };
+    }
+
+    /* (non-Javadoc)
+     * @see edu.uci.ics.asterix.om.functions.AbstractFunctionDescriptor#getIdentifier()
+     */
+    @Override
+    public FunctionIdentifier getIdentifier() {
+        return isGreaterThan ? GREATER_THAN_FID : LESS_THAN_FID;
+    }
+
+}
diff --git a/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/formats/NonTaggedDataFormat.java b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/formats/NonTaggedDataFormat.java
index a61208d..84142be 100644
--- a/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/formats/NonTaggedDataFormat.java
+++ b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/formats/NonTaggedDataFormat.java
@@ -203,6 +203,10 @@
 import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.DateFromUnixTimeInDaysDescriptor;
 import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.DatetimeFromDateAndTimeDescriptor;
 import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.DatetimeFromUnixTimeInMsDescriptor;
+import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.DayTimeDurationComparatorDescriptor;
+import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.DurationEqualDescriptor;
+import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.DurationFromMillisecondsDescriptor;
+import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.DurationFromMonthsDescriptor;
 import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.IntervalAfterDescriptor;
 import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.IntervalBeforeDescriptor;
 import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.IntervalCoveredByDescriptor;
@@ -211,6 +215,8 @@
 import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.IntervalEndsDecriptor;
 import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.IntervalMeetsDescriptor;
 import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.IntervalMetByDescriptor;
+import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.MillisecondsOfDayTimeDurationDescriptor;
+import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.MonthsOfYearMonthDurationDescriptor;
 import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.OverlapDescriptor;
 import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.IntervalOverlappedByDescriptor;
 import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.IntervalOverlapsDescriptor;
@@ -221,6 +227,7 @@
 import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.SubtractTimeDescriptor;
 import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.TimeFromDatetimeDescriptor;
 import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.TimeFromUnixTimeInMsDescriptor;
+import edu.uci.ics.asterix.runtime.evaluators.functions.temporal.YearMonthDurationComparatorDecriptor;
 import edu.uci.ics.asterix.runtime.operators.file.AdmSchemafullRecordParserFactory;
 import edu.uci.ics.asterix.runtime.operators.file.NtDelimitedDataTupleParserFactory;
 import edu.uci.ics.asterix.runtime.runningaggregates.std.TidRunningAggregateDescriptor;
@@ -502,6 +509,15 @@
         temp.add(CurrentDateDescriptor.FACTORY);
         temp.add(CurrentTimeDescriptor.FACTORY);
         temp.add(CurrentDateTimeDescriptor.FACTORY);
+        temp.add(DurationFromMillisecondsDescriptor.FACTORY);
+        temp.add(DurationFromMonthsDescriptor.FACTORY);
+        temp.add(YearMonthDurationComparatorDecriptor.GREATER_THAN_FACTORY);
+        temp.add(YearMonthDurationComparatorDecriptor.LESS_THAN_FACTORY);
+        temp.add(DayTimeDurationComparatorDescriptor.GREATER_THAN_FACTORY);
+        temp.add(DayTimeDurationComparatorDescriptor.LESS_THAN_FACTORY);
+        temp.add(MonthsOfYearMonthDurationDescriptor.FACTORY);
+        temp.add(MillisecondsOfDayTimeDurationDescriptor.FACTORY);
+        temp.add(DurationEqualDescriptor.FACTORY);
 
         // Interval constructor
         temp.add(AIntervalFromDateConstructorDescriptor.FACTORY);