Code :
QDateTime eventDate = dateTodo->dateTime();
           QString todoName = list.at(1);
           KCal::Event *myEvent = new KCal::Event();
           myEvent->setDuration(3600);
           myEvent->setFloats(FALSE);
           myEvent->setDtStart(eventDate);
           myEvent->setSummary(todoName);
           m_calendar->addEvent(myEvent);
           m_calendar->save("cal.ics");
           lstWdgTodoList->addItem(todoName);





BEGIN:VCALENDAR
PRODID:-//K Desktop Environment//NONSGML libkcal 3.5//EN
VERSION:2.0
BEGIN:VEVENT
DTSTAMP:20070327T162115Z
CREATED:20070327T161846Z
UID:libkcal-1702932553.1038
LAST-MODIFIED:20070327T161846Z
SUMMARY:t
DURATION:PT1H
DTSTART;TZID=Asia/Shanghai:20000101T000000
TRANSP:OPAQUE
END:VEVENT

BEGIN:VTIMEZONE
TZID:Asia/Shanghai
BEGIN:STANDARD
TZNAME:CST
TZOFFSETFROM:+080552
TZOFFSETTO:+0800
DTSTART:19280101T155408
RDATE;VALUE=DATE-TIME:19280101T155408
END:STANDARD

BEGIN:DAYLIGHT
TZNAME:CDT
TZOFFSETFROM:+0800
TZOFFSETTO:+0900
DTSTART:19400603T160000
RDATE;VALUE=DATE-TIME:19400603T160000
RDATE;VALUE=DATE-TIME:19410316T160000
RDATE;VALUE=DATE-TIME:19860503T160000
RDATE;VALUE=DATE-TIME:19870411T160000
RDATE;VALUE=DATE-TIME:19880409T160000
RDATE;VALUE=DATE-TIME:19890415T160000
RDATE;VALUE=DATE-TIME:19900414T160000
RDATE;VALUE=DATE-TIME:19910413T160000
END:DAYLIGHT

BEGIN:STANDARD
TZNAME:CST
TZOFFSETFROM:+0900
TZOFFSETTO:+0800
DTSTART:19401001T150000
RDATE;VALUE=DATE-TIME:19401001T150000
RDATE;VALUE=DATE-TIME:19411001T150000
RDATE;VALUE=DATE-TIME:19860913T150000
RDATE;VALUE=DATE-TIME:19870912T150000
RDATE;VALUE=DATE-TIME:19880910T150000
RDATE;VALUE=DATE-TIME:19890916T150000
RDATE;VALUE=DATE-TIME:19900915T150000
RDATE;VALUE=DATE-TIME:19910914T150000
END:STANDARD


END:VTIMEZONE

END:VCALENDAR