diff --git a/src/main/java/org/gcube/accounting/aggregation/AggregatedJobUsageRecord.java b/src/main/java/org/gcube/accounting/aggregation/AggregatedJobUsageRecord.java
index 3497508..9addb05 100644
--- a/src/main/java/org/gcube/accounting/aggregation/AggregatedJobUsageRecord.java
+++ b/src/main/java/org/gcube/accounting/aggregation/AggregatedJobUsageRecord.java
@@ -4,6 +4,7 @@
 package org.gcube.accounting.aggregation;
 
 import java.io.Serializable;
+import java.util.Calendar;
 import java.util.Map;
 
 import org.gcube.accounting.datamodel.AggregatedUsageRecord;
@@ -56,5 +57,37 @@ public class AggregatedJobUsageRecord extends AbstractJobUsageRecord implements
 		return null;
 	}
 
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public Calendar getStartTime() {
+		return getStartTimeAsCalendar();
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public void setStartTime(Calendar startTime) throws InvalidValueException {
+		super.setStartTime(startTime);
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public Calendar getEndTimeAsCalendar() {
+		return getEndTimeAsCalendar();
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public void setEndTime(Calendar endTime) throws InvalidValueException {
+		super.setEndTime(endTime);
+	}
+
 	
 }
diff --git a/src/main/java/org/gcube/accounting/aggregation/AggregatedPortletUsageRecord.java b/src/main/java/org/gcube/accounting/aggregation/AggregatedPortletUsageRecord.java
index 8f5c903..8971ef2 100644
--- a/src/main/java/org/gcube/accounting/aggregation/AggregatedPortletUsageRecord.java
+++ b/src/main/java/org/gcube/accounting/aggregation/AggregatedPortletUsageRecord.java
@@ -4,6 +4,7 @@
 package org.gcube.accounting.aggregation;
 
 import java.io.Serializable;
+import java.util.Calendar;
 import java.util.Map;
 
 import org.gcube.accounting.datamodel.AggregatedUsageRecord;
@@ -56,5 +57,37 @@ public class AggregatedPortletUsageRecord extends AbstractPortletUsageRecord imp
 		// TODO Auto-generated method stub
 		return null;
 	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public Calendar getStartTime() {
+		return getStartTimeAsCalendar();
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public void setStartTime(Calendar startTime) throws InvalidValueException {
+		super.setStartTime(startTime);
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public Calendar getEndTimeAsCalendar() {
+		return getEndTimeAsCalendar();
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public void setEndTime(Calendar endTime) throws InvalidValueException {
+		super.setEndTime(endTime);
+	}
 
 }
diff --git a/src/main/java/org/gcube/accounting/aggregation/AggregatedServiceUsageRecord.java b/src/main/java/org/gcube/accounting/aggregation/AggregatedServiceUsageRecord.java
index 101acba..6dae65a 100644
--- a/src/main/java/org/gcube/accounting/aggregation/AggregatedServiceUsageRecord.java
+++ b/src/main/java/org/gcube/accounting/aggregation/AggregatedServiceUsageRecord.java
@@ -97,4 +97,36 @@ public class AggregatedServiceUsageRecord extends AbstractServiceUsageRecord imp
 		return new AggregatedServiceUsageRecord(usageRecord);
 	}
 	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public Calendar getStartTime() {
+		return getStartTimeAsCalendar();
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public void setStartTime(Calendar startTime) throws InvalidValueException {
+		super.setStartTime(startTime);
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public Calendar getEndTimeAsCalendar() {
+		return getEndTimeAsCalendar();
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public void setEndTime(Calendar endTime) throws InvalidValueException {
+		super.setEndTime(endTime);
+	}
+	
 }
diff --git a/src/main/java/org/gcube/accounting/aggregation/AggregatedStorageUsageRecord.java b/src/main/java/org/gcube/accounting/aggregation/AggregatedStorageUsageRecord.java
index fffa230..0981628 100644
--- a/src/main/java/org/gcube/accounting/aggregation/AggregatedStorageUsageRecord.java
+++ b/src/main/java/org/gcube/accounting/aggregation/AggregatedStorageUsageRecord.java
@@ -74,4 +74,36 @@ public class AggregatedStorageUsageRecord extends AbstractStorageUsageRecord imp
 		return new AggregatedStorageUsageRecord(usageRecord);
 	}
 	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public Calendar getStartTime() {
+		return getStartTimeAsCalendar();
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public void setStartTime(Calendar startTime) throws InvalidValueException {
+		super.setStartTime(startTime);
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public Calendar getEndTimeAsCalendar() {
+		return getEndTimeAsCalendar();
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public void setEndTime(Calendar endTime) throws InvalidValueException {
+		super.setEndTime(endTime);
+	}
+	
 }
diff --git a/src/main/java/org/gcube/accounting/aggregation/AggregatedTaskUsageRecord.java b/src/main/java/org/gcube/accounting/aggregation/AggregatedTaskUsageRecord.java
index fc71c55..47747ef 100644
--- a/src/main/java/org/gcube/accounting/aggregation/AggregatedTaskUsageRecord.java
+++ b/src/main/java/org/gcube/accounting/aggregation/AggregatedTaskUsageRecord.java
@@ -4,6 +4,7 @@
 package org.gcube.accounting.aggregation;
 
 import java.io.Serializable;
+import java.util.Calendar;
 import java.util.Map;
 
 import org.gcube.accounting.datamodel.AggregatedUsageRecord;
@@ -56,5 +57,37 @@ public class AggregatedTaskUsageRecord extends AbstractTaskUsageRecord implement
 		// TODO Auto-generated method stub
 		return null;
 	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public Calendar getStartTime() {
+		return getStartTimeAsCalendar();
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public void setStartTime(Calendar startTime) throws InvalidValueException {
+		super.setStartTime(startTime);
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public Calendar getEndTimeAsCalendar() {
+		return getEndTimeAsCalendar();
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public void setEndTime(Calendar endTime) throws InvalidValueException {
+		super.setEndTime(endTime);
+	}
 
 }
diff --git a/src/main/java/org/gcube/accounting/datamodel/AggregatedUsageRecord.java b/src/main/java/org/gcube/accounting/datamodel/AggregatedUsageRecord.java
index b16ce17..bdd7d29 100644
--- a/src/main/java/org/gcube/accounting/datamodel/AggregatedUsageRecord.java
+++ b/src/main/java/org/gcube/accounting/datamodel/AggregatedUsageRecord.java
@@ -3,6 +3,8 @@
  */
 package org.gcube.accounting.datamodel;
 
+import java.util.Calendar;
+
 import org.gcube.accounting.datamodel.decorators.AggregatedField;
 import org.gcube.accounting.datamodel.validations.annotations.ValidInteger;
 import org.gcube.accounting.exception.InvalidValueException;
@@ -21,4 +23,12 @@ public interface AggregatedUsageRecord<T extends AggregatedUsageRecord<T, B>, B
 	
 	public void setOperationCount(int operationCount) throws InvalidValueException;
 
+	public Calendar getStartTime();
+	
+	public void setStartTime(Calendar startTime) throws InvalidValueException;
+	
+	public Calendar getEndTimeAsCalendar();
+	
+	public void setEndTime(Calendar endTime) throws InvalidValueException;
+	
 }