=== modified file 'dhis-2/dhis-api/src/main/java/org/hisp/dhis/calendar/Calendar.java'
--- dhis-2/dhis-api/src/main/java/org/hisp/dhis/calendar/Calendar.java	2014-04-24 17:18:03 +0000
+++ dhis-2/dhis-api/src/main/java/org/hisp/dhis/calendar/Calendar.java	2014-04-25 06:29:27 +0000
@@ -50,4 +50,12 @@
     int daysInYear( int year );
 
     int daysInMonth( int year, int month );
+
+    int isoWeek( DateUnit dateUnit );
+
+    int week( DateUnit dateUnit );
+
+    int isoWeekday( DateUnit dateUnit );
+
+    int weekday( DateUnit dateUnit );
 }

=== modified file 'dhis-2/dhis-api/src/main/java/org/hisp/dhis/calendar/ChronologyBasedCalendar.java'
--- dhis-2/dhis-api/src/main/java/org/hisp/dhis/calendar/ChronologyBasedCalendar.java	2014-04-24 17:18:03 +0000
+++ dhis-2/dhis-api/src/main/java/org/hisp/dhis/calendar/ChronologyBasedCalendar.java	2014-04-25 06:29:27 +0000
@@ -56,9 +56,7 @@
     @Override
     public DateUnit fromIso( DateUnit dateUnit )
     {
-        DateTime dateTime = dateUnit.toDateTime();
-        dateTime = dateTime.withChronology( chronology );
-
+        DateTime dateTime = dateUnit.toDateTime( chronology );
         return DateUnit.fromDateTime( dateTime );
     }
 
@@ -89,4 +87,30 @@
         DateTime dateTime = new DateTime( year, month, 1, 0, 0, chronology );
         return (int) dateTime.monthOfYear().toInterval().toDuration().getStandardDays();
     }
+
+    @Override
+    public int isoWeek( DateUnit dateUnit )
+    {
+        DateTime dateTime = dateUnit.toDateTime( chronology );
+        return dateTime.getWeekOfWeekyear();
+    }
+
+    @Override
+    public int week( DateUnit dateUnit )
+    {
+        return isoWeek( dateUnit );
+    }
+
+    @Override
+    public int isoWeekday( DateUnit dateUnit )
+    {
+        DateTime dateTime = dateUnit.toDateTime( chronology );
+        return dateTime.getDayOfWeek();
+    }
+
+    @Override
+    public int weekday( DateUnit dateUnit )
+    {
+        return isoWeekday( dateUnit );
+    }
 }

=== added file 'dhis-2/dhis-api/src/main/java/org/hisp/dhis/calendar/DateInterval.java'
--- dhis-2/dhis-api/src/main/java/org/hisp/dhis/calendar/DateInterval.java	1970-01-01 00:00:00 +0000
+++ dhis-2/dhis-api/src/main/java/org/hisp/dhis/calendar/DateInterval.java	2014-04-25 06:29:27 +0000
@@ -0,0 +1,63 @@
+package org.hisp.dhis.calendar;
+
+/*
+ * Copyright (c) 2004-2014, University of Oslo
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ * Neither the name of the HISP project nor the names of its contributors may
+ * be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * @author Morten Olav Hansen <mortenoh@gmail.com>
+ */
+public class DateInterval
+{
+    private final DateUnit from;
+
+    private final DateUnit to;
+
+    public DateInterval( DateUnit from, DateUnit to )
+    {
+        this.from = from;
+        this.to = to;
+    }
+
+    public DateUnit getFrom()
+    {
+        return from;
+    }
+
+    public DateUnit getTo()
+    {
+        return to;
+    }
+
+    @Override public String toString()
+    {
+        return "DateInterval{" +
+            "from=" + from +
+            ", to=" + to +
+            '}';
+    }
+}

=== modified file 'dhis-2/dhis-api/src/main/java/org/hisp/dhis/calendar/NepaliCalendar.java'
--- dhis-2/dhis-api/src/main/java/org/hisp/dhis/calendar/NepaliCalendar.java	2014-04-24 17:18:03 +0000
+++ dhis-2/dhis-api/src/main/java/org/hisp/dhis/calendar/NepaliCalendar.java	2014-04-25 06:29:27 +0000
@@ -30,6 +30,7 @@
 
 import org.joda.time.DateTime;
 import org.joda.time.Days;
+import org.joda.time.chrono.ISOChronology;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -131,6 +132,39 @@
         return conversionMap.get( year )[month];
     }
 
+    @Override
+    public int isoWeek( DateUnit dateUnit )
+    {
+        DateTime dateTime = toIso( dateUnit ).toDateTime( ISOChronology.getInstance() );
+        return dateTime.getWeekyear();
+    }
+
+    @Override
+    public int week( DateUnit dateUnit )
+    {
+        return isoWeek( dateUnit );
+    }
+
+    @Override
+    public int isoWeekday( DateUnit dateUnit )
+    {
+        DateTime dateTime = toIso( dateUnit ).toDateTime( ISOChronology.getInstance() );
+        return dateTime.getDayOfWeek();
+    }
+
+    @Override
+    public int weekday( DateUnit dateUnit )
+    {
+        int dayOfWeek = (isoWeekday( dateUnit ) + 1);
+
+        if ( dayOfWeek > 7 )
+        {
+            return 1;
+        }
+
+        return dayOfWeek;
+    }
+
     private int getYearTotal( int year )
     {
         // if year total index is uninitialized, calculate and set in array