Exchange admins: DST 2007 change.. this is confusing

mike2323

Weaksauce
Joined
Sep 2, 2004
Messages
121
I'm looking over the DST 2007 changes and came across this:

http://support.microsoft.com/kb/930879/

I am absolutely confused as to why this tool is necessary. When the time change hits on March 11th, are Exchange calendar items going to switch their times on their own? I really do not get this.

1) As of today I have a meeting scheduled for 9am of 03/12/07.
2) Time change occurs on 03/11/07 and time moves forward 1 hour.
3) My meeting is still scheduled for 9am of 03/12/07.

It doesn't make sense to me.. is Outlook going to move all appointments forward 1 hour? There is absolutely no logic in that.
 
It doesn't make sense to me.. is Outlook going to move all appointments forward 1 hour? There is absolutely no logic in that.

Think of it this way:

You're based in New York, and you make an appointment for a conference call a 1PM on Friday. Then you fly to your branch office in LA. Now, if you try to make this call at 1PM local time, it's going to be 4PM in New York, so that won't work.

What Outlook/Exchange do is to keep calendars in a time neutral (UT?) format, and then display times based on time zone information.

Daylight saving time was a special case, because you're essentially changing a time zone without changing the time of an event. For example, a 1PM appointment would still be a 1PM appointment even though your time zone may have gone from GMT+6 to GMT+5. Outlook had some special rules for that built in, based on the beginning and ending dates of DST.

Now the dates of DST have changed, so you might have some events that need to be fixed according to the new rules. That's what all these new tools from MS are for, to clean up this mess.
 
I don't feel bad bringing this thread back to life because it relates exactly to a question I had today from a user.

Question:
User is scheduling a meeting today for Monday 3/15/10 at 09:00 AM Eastern Time.
Person on the other end of the meeting invite is in Mexico. They do not do DST and are in Central America Time.
This weekend, what will happen to the meeting invite? Will it stay 09:00 AM Eastern Time? Will it go backwards one hour for the Mexican? Or will it move to 10:00 AM Eastern Time and stay at 07:00 AM Central America Time?

:confused::confused::confused::confused:
 
Provided the relevant servers are patched/configured for the correct local changes to the time it will reflect the correct local time for each user, so if it was 1pm EST it will still be 1pm EST after the DST change.
 
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