diff -r dee028db6e9b -r 73bdfa70b04e src/net/fortuna/ical4j/model/component/VEvent.java
--- a/src/net/fortuna/ical4j/model/component/VEvent.java	Tue Feb 10 19:25:00 2015 +0100
+++ b/src/net/fortuna/ical4j/model/component/VEvent.java	Tue Feb 10 19:38:00 2015 +0100
@@ -548,7 +548,6 @@
             
             PropertyValidator.getInstance().assertOneOrLess(Property.CATEGORIES, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.CLASS, getProperties());
-            PropertyValidator.getInstance().assertOneOrLess(Property.COMMENT, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.CREATED, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.DESCRIPTION, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.DTEND, getProperties());
@@ -643,7 +642,6 @@
             PropertyValidator.getInstance().assertOne(Property.SEQUENCE, getProperties());
             PropertyValidator.getInstance().assertOne(Property.UID, getProperties());
             
-            PropertyValidator.getInstance().assertOneOrLess(Property.COMMENT, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.CATEGORIES, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.CLASS, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.CREATED, getProperties());
@@ -747,7 +745,6 @@
             
             PropertyValidator.getInstance().assertOneOrLess(Property.CATEGORIES, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.CLASS, getProperties());
-            PropertyValidator.getInstance().assertOneOrLess(Property.COMMENT, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.CREATED, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.DESCRIPTION, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.DTEND, getProperties());
@@ -833,7 +830,6 @@
             PropertyValidator.getInstance().assertOne(Property.ORGANIZER, getProperties());
             PropertyValidator.getInstance().assertOne(Property.UID, getProperties());
             
-            PropertyValidator.getInstance().assertOneOrLess(Property.COMMENT, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.RECURRENCE_ID, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.SEQUENCE, getProperties());
             
@@ -941,7 +937,6 @@
             PropertyValidator.getInstance().assertOneOrLess(Property.SEQUENCE, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.CATEGORIES, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.CLASS, getProperties());
-            PropertyValidator.getInstance().assertOneOrLess(Property.COMMENT, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.CREATED, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.DESCRIPTION, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.DTEND, getProperties());
@@ -1034,7 +1029,6 @@
             PropertyValidator.getInstance().assertOne(Property.ORGANIZER, getProperties());
             PropertyValidator.getInstance().assertOne(Property.UID, getProperties());
             
-            PropertyValidator.getInstance().assertOneOrLess(Property.COMMENT, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.RECURRENCE_ID, getProperties());
             
             PropertyValidator.getInstance().assertNone(Property.ATTACH, getProperties());
@@ -1140,7 +1134,6 @@
             PropertyValidator.getInstance().assertOneOrLess(Property.SEQUENCE, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.CATEGORIES, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.CLASS, getProperties());
-            PropertyValidator.getInstance().assertOneOrLess(Property.COMMENT, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.CREATED, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.DESCRIPTION, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.DTEND, getProperties());
@@ -1233,7 +1226,6 @@
             PropertyValidator.getInstance().assertOneOrLess(Property.SEQUENCE, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.CATEGORIES, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.CLASS, getProperties());
-            PropertyValidator.getInstance().assertOneOrLess(Property.COMMENT, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.CREATED, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.DESCRIPTION, getProperties());
             PropertyValidator.getInstance().assertOneOrLess(Property.DTEND, getProperties());
@@ -1456,9 +1448,19 @@
     public final DtEnd getEndDate(final boolean deriveFromDuration) {
         DtEnd dtEnd = (DtEnd) getProperty(Property.DTEND);
         // No DTEND? No problem, we'll use the DURATION.
-        if (dtEnd == null && deriveFromDuration && getDuration() != null) {
+        if (dtEnd == null && deriveFromDuration && getStartDate() != null) {
             final DtStart dtStart = getStartDate();
-            final Duration vEventDuration = getDuration();
+            final Duration vEventDuration;
+            if (getDuration() != null) {
+                vEventDuration = getDuration();
+            } else if (dtStart.getDate() instanceof DateTime) {
+                // If "DTSTART" is a DATE-TIME, then the event's duration is zero (see: RFC 5545, 3.6.1 Event Component)
+                vEventDuration = new Duration(new Dur(0, 0, 0, 0));
+            } else {
+                // If "DTSTART" is a DATE, then the event's duration is one day (see: RFC 5545, 3.6.1 Event Component)
+                vEventDuration = new Duration(new Dur(1, 0, 0, 0));
+            }
+
             dtEnd = new DtEnd(Dates.getInstance(vEventDuration.getDuration()
                     .getTime(dtStart.getDate()), (Value) dtStart
                     .getParameter(Parameter.VALUE)));