I’ve read all the docs pertaining to DST but I am still confused, I’m sure that I am missing something critical here.I have begun testing in a dev environment how the agents work for the resoruce reservations db as well as with the mailboxes. The agents appaer to run and make changes.
My confusion is this:
I ran the agent on the resource reservations db that I put a bunch of test reservations into. The agent adjusted all the meetings in the 3 week transition time by one hour. So a meeting that was prviously scheduled to start at 10am has now been adjusted to 9am. Why would we want this to happen, we want the meeting at 10am not 9am no matter if DST is in effect or not. The Windows clients are all going to update their time properly on the 11th (we patched them already). Staff are still going to work their normal 8am-5pm or whatever shifts come Monday. Why move our meeting times off by an hour?
Subject: DST Confusion
Hi Chris - Good question posed -
So, the answer is that when you look at actual time the meeting is scheduled, you would need to see an absolute change in order to keep the actual time consistent. That is, if you have a totally unpatched system and schedule a room reservation for 9:00 AM Eastern Standard Time (EST) for 3/12/2007 it would be stored as stated. Then, when you update your client OS that meeting would APPEAR to be scheduled at 10:00 AM Eastern Daylight Time (EDT), but it would be incorrect because the absolute time is still recording the EDT. The agent will correct that document to put it “forward” to 9:00 AM.
The reverse is also true - If you scheduled a meeting or room using the new time zone rules, or updated an “old” entry with the agent, it will look an hour “early” unless the OS is patched correctly.
It’s critical that BOTH happen. To check and see what rules are being used to create new entries just have a quick look at the StartTimeZone field on a newly created document. If you are creating entries with new rules and you don’t see them displayed correctly in the view then have a look at the registry key (insert your fav. edit registry at your own risk/caution disclaimer here)
[-HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation]
HTH
Subject: DST Confusion
I like to see things, to help understand so maybe some pictures will clear things up.
As of today my PC has had the windows patch applied. Therefore, if I create a meeting for next week on the 14th, from 3pm - 4pm Eastern it will show up on my calendar as 3pm - 4pm EDT (Eastern Daylight Time):
However, earlier in the year before I applied the windows patch, I booked a meeting for the 14th from 3-4pm Eastern. At the time, the system didn’t think Daylight time didn’t start until 3 weeks later. So the meeting got created and stored as 3-4pm EST.
Given that we now know that on March 14 we will be observing EDT. On March 14 3pm EST is acutally 4pm EDT. Therefore, if we don’t move the meeting up by one hour, I will miss the meeting as my alarm won’t go off until 4pm EDT = 3pm EST.
We see this by opening the actual meeting.
While the meeting says it takes place at 3pm, notice the Local time says 4-5pm local time.
The fix therefore should only be applied to documents created BEFORE the timezone fix has been applied. Any documents created after the timezone patch will be fine.
Subject: RE: DST Confusion
Thank you Steven and Michael for your wonderful explanations, it all makes sense now. If I was a cartoon character the light bulb would have just lit up over my head. I didn’t even notice that some of the meetings were EST while others were EDT. And to make matters worse the test client that I was using didn’t have the DSL Windows patch on it which I thought it did. Once I ran Windows Update all the times went to their proper hours!
Thank you!!!