Add To Calendar links

{EVENTNAME}: Replace with Event Name
{EVENTDESC}: Replace with Event Description
{YYYYMMDD}T{HHMMSS}: Replace with date/time of Event start/end in exact format. Yahoo use duration instead of end date/time.
{VENUE}: Veneue of Event

Google
https://calendar.google.com/calendar/render?action=TEMPLATE&trp=false&sprop=website%20address&sprop=name:website%20name&text={EVENTNAME}&dates={YYYYMMDD}T{HHMMSS}/{YYYYMMDD}T{HHMMSS}&details={EVENTDESC}&location={VENUE}

Hotmail
http://calendar.live.com/calendar/calendar.aspx?rru=addevent&dtstart={YYYYMMDD}T{HHMMSS}&TITLE={EVENTNAME}&DUR={HHMM}&VIEW=d&DESC={EVENTDESC}&in_loc={VENUE}&dtend={YYYYMMDD}T{HHMMSS}&summary={EVENTNAME}&location={VENUE}

Yahoo
http://calendar.yahoo.com/?v=60&ST={YYYYMMDD}T{HHMMSS}&TITLE={EVENTNAME}&DUR={HHMM}&VIEW=d&DESC={EVENTDESC}&in_loc={VENUE}