ICalendar and event updates not working in Outlook

Question

I\'m generating ICalendar (.ics) files.

Using the UID and SEQUENCE fields I can update existing events in Google Calendar and in Windows Calendar BUT NOT

Answer 1

I am using outlook 2003 (from reading the posts, 2007 appears to behave in the same way) and you need to clearly distinguish between the behaviour of the explicit file import of an ics file and the implicit import when an ics file is 'double clicked'.

On the Outlook menu File / Import and Export ... Outlook will load as many VEVENT entries as are in the file and no amount of changing UID:, SEQUENCE: or DTSTAMP: values changes this, i.e.if you change any data and re-import it you just get a duplicate set of entries.

If you double click on an ics file it processes the first VEVENT entry only. However it does recognise the UID and, if the DTSTAMP: is later (the SEQUENCE can be the same but not lower) you will be prompted and it will update the event in your calendar.

BEGIN:VCALENDAR
VERSION:2.0
PRODID:www.membership-services.net
METHOD:REQUEST
BEGIN:VEVENT
DTSTART:20090126T210000
DTEND:20090126T220000
SUMMARY:Avondale - Thameside Away Game vs Croydon
LOCATION:Whitgift School
DESCRIPTION:http://maps.google.co.uk/maps?f=q&hl=en&geocode=&q=CR2+6YT 
UID:AWPC_8
SEQUENCE:0
DTSTAMP:20090123T112600
END:VEVENT
BEGIN:VEVENT
DTSTART:20090202T213000
DTEND:20090202T223000
SUMMARY:Avondale - Thameside Home Game vs Orcas
LOCATION:Putney
DESCRIPTION:http://maps.google.co.uk/maps?f=q&source=s_q&hl=en&ie=UTF8&ll=51.4635,-0.2285&spn=0.005,0.009613&t=h&z=17&iwloc=lyrftr:w2t.90,0x48760f04a04b1801:0x49ebf12503a5d5a9,51.463459,-0.228674 
UID:AWPC_10
SEQUENCE:0
DTSTAMP:20090123T112600
END:VEVENT
END:VCALENDAR