Then I installed the Sharepoint patch on the server – all was well. http://support.microsoft.com/default.aspx?scid=kb;en-us;924881 Expected this for Outlook.. no worries… Users will then either manually change the Calendar time zone (available from the ‘Calendar Options…’ dialog on Tools | Options) or respond to the automatic prompts to change their Calendar time zone that will occur 1 to 7 days after the DST rules are updated on the machine.Began test. Set an appointment at 4/1/2007 at 1 a.m. Invited everyone in the office, told them to “accept” the invitation. Told the Secretaries to go look at everyone’s calendars (they have full rights to do so) to see if everyone’s calendar had a 1 a.m. appointment on 4/1/2007. All was well.Then had the folks with Windows Mobile 3 phones to check what time/date that 1 a.m. meeting was.Houston …we have a problem. Their appointment was for Midnight on 4/1/2007. Uh oh….the phones need a patch. http://support.microsoft.com/kb/923953Blackberry folks look like they are going to have to manually make the change, http://www.blackberryforums.com/bes-admin-corner/60258-impact-north-american-daylight-saving-time-changes-2007-blackberry-device-us.html in which case you might want to wait to apply those time patches as obviously they do have impact.Kevin reported that http://pdaphonehome.com/ already had an OS based patch for his Samsung device http://pdaphonehome.com/forums/samsung-i730-i830-i830w/81246-2007-time-zone-update-information-wm-devices.html?highlight=timezoneGiven that my main phones are brands no longer even sold… I’ll have to do some digging and see what my options are. Start, run, regedit on my phone just isn’t quite what I had in mind….