diff -r 000000000000 -r fb9019fb1bf7 src/net/fortuna/ical4j/model/property/DtStart.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/net/fortuna/ical4j/model/property/DtStart.java	Tue Feb 10 18:12:00 2015 +0100
@@ -0,0 +1,205 @@
+/**
+ * Copyright (c) 2012, Ben Fortuna
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *  o Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ *  o 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.
+ *
+ *  o Neither the name of Ben Fortuna nor the names of any other 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.
+ */
+package net.fortuna.ical4j.model.property;
+
+import java.text.ParseException;
+
+import net.fortuna.ical4j.model.Date;
+import net.fortuna.ical4j.model.ParameterList;
+import net.fortuna.ical4j.model.PropertyFactoryImpl;
+import net.fortuna.ical4j.model.TimeZone;
+import net.fortuna.ical4j.model.ValidationException;
+
+/**
+ * $Id$
+ * 
+ * Created: [Apr 6, 2004]
+ *
+ * Defines a DTSTART iCalendar component property.
+ * 
+ * <pre>
+ *     4.8.2.4 Date/Time Start
+ *     
+ *        Property Name: DTSTART
+ *     
+ *        Purpose: This property specifies when the calendar component begins.
+ *     
+ *        Value Type: The default value type is DATE-TIME. The time value MUST
+ *        be one of the forms defined for the DATE-TIME value type. The value
+ *        type can be set to a DATE value type.
+ *     
+ *        Property Parameters: Non-standard, value data type, time zone
+ *        identifier property parameters can be specified on this property.
+ *     
+ *        Conformance: This property can be specified in the &quot;VEVENT&quot;, &quot;VTODO&quot;,
+ *        &quot;VFREEBUSY&quot;, or &quot;VTIMEZONE&quot; calendar components.
+ *     
+ *        Description: Within the &quot;VEVENT&quot; calendar component, this property
+ *        defines the start date and time for the event. The property is
+ *        REQUIRED in &quot;VEVENT&quot; calendar components. Events can have a start
+ *        date/time but no end date/time. In that case, the event does not take
+ *        up any time.
+ *     
+ *        Within the &quot;VFREEBUSY&quot; calendar component, this property defines the
+ *        start date and time for the free or busy time information. The time
+ *        MUST be specified in UTC time.
+ *     
+ *        Within the &quot;VTIMEZONE&quot; calendar component, this property defines the
+ *        effective start date and time for a time zone specification. This
+ *        property is REQUIRED within each STANDARD and DAYLIGHT part included
+ *        in &quot;VTIMEZONE&quot; calendar components and MUST be specified as a local
+ *        DATE-TIME without the &quot;TZID&quot; property parameter.
+ *     
+ *        Format Definition: The property is defined by the following notation:
+ *     
+ *          dtstart    = &quot;DTSTART&quot; dtstparam &quot;:&quot; dtstval CRLF
+ *     
+ *          dtstparam  = *(
+ *     
+ *                     ; the following are optional,
+ *                     ; but MUST NOT occur more than once
+ *     
+ *                     (&quot;;&quot; &quot;VALUE&quot; &quot;=&quot; (&quot;DATE-TIME&quot; / &quot;DATE&quot;)) /
+ *                     (&quot;;&quot; tzidparam) /
+ *     
+ *                     ; the following is optional,
+ *                     ; and MAY occur more than once
+ *     
+ *                       *(&quot;;&quot; xparam)
+ *     
+ *                     )
+ *     
+ *     
+ *     
+ *          dtstval    = date-time / date
+ *          ;Value MUST match value type
+ * </pre>
+ * 
+ * @author Ben Fortuna
+ */
+public class DtStart extends DateProperty {
+
+    private static final long serialVersionUID = -5707097476081111815L;
+
+    /**
+     * Default constructor. The time value is initialised to the time of instantiation.
+     */
+    public DtStart() {
+        super(DTSTART, PropertyFactoryImpl.getInstance());
+    }
+
+    /**
+     * Creates a new DTSTART property initialised with the specified timezone.
+     * @param timezone initial timezone
+     */
+    public DtStart(TimeZone timezone) {
+        super(DTSTART, timezone, PropertyFactoryImpl.getInstance());
+    }
+
+    /**
+     * @param aValue a value string for this component
+     * @throws ParseException where the specified value string is not a valid date-time/date representation
+     */
+    public DtStart(final String aValue) throws ParseException {
+        super(DTSTART, PropertyFactoryImpl.getInstance());
+        setValue(aValue);
+    }
+
+    /**
+     * Creates a new DTSTART property initialised with the specified timezone and value.
+     * @param value a string representation of a DTSTART value
+     * @param timezone initial timezone
+     * @throws ParseException where the specified value is not a valid string
+     * representation
+     */
+    public DtStart(String value, TimeZone timezone) throws ParseException {
+        super(DTSTART, timezone, PropertyFactoryImpl.getInstance());
+        setValue(value);
+    }
+
+    /**
+     * @param aList a list of parameters for this component
+     * @param aValue a value string for this component
+     * @throws ParseException where the specified value string is not a valid date-time/date representation
+     */
+    public DtStart(final ParameterList aList, final String aValue)
+            throws ParseException {
+        super(DTSTART, aList, PropertyFactoryImpl.getInstance());
+        setValue(aValue);
+    }
+
+    /**
+     * Constructor. Date or Date-Time format is determined based on the presence of a VALUE parameter.
+     * @param aDate a date
+     */
+    public DtStart(final Date aDate) {
+        super(DTSTART, PropertyFactoryImpl.getInstance());
+        setDate(aDate);
+    }
+
+    /**
+     * Constructs a new DtStart with the specified time.
+     * @param time the time of the DtStart
+     * @param utc specifies whether time is UTC
+     */
+    public DtStart(final Date time, final boolean utc) {
+        super(DTSTART, PropertyFactoryImpl.getInstance());
+        setDate(time);
+        setUtc(utc);
+    }
+
+    /**
+     * Constructor. Date or Date-Time format is determined based on the presence of a VALUE parameter.
+     * @param aList a list of parameters for this component
+     * @param aDate a date
+     */
+    public DtStart(final ParameterList aList, final Date aDate) {
+        super(DTSTART, aList, PropertyFactoryImpl.getInstance());
+        setDate(aDate);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public final void validate() throws ValidationException {
+        super.validate();
+
+        /*
+         * ; the following are optional, ; but MUST NOT occur more than once (";" "VALUE" "=" ("DATE-TIME" / "DATE")) /
+         * (";" tzidparam) /
+         */
+
+        /*
+         * ; the following is optional, ; and MAY occur more than once (";" xparam)
+         */
+    }
+}