DST 2007: I rebased appointments and nothing moved!

by Bharat Suneja

It’s natural to question what the rebasing tools did – after you rebased items, they didn’t seem to move them! Appointments show up in their correct time slots.

Wasn’t this what you wanted to see – appointments appear in their correct time slots? :)

I’ve covered this in a previous post titled “DST 2007: Understanding what needs to be done and how to do it“, and I’ll briefly explain what happens once again.

– User workstation has older DST 2006 time zone rules, all appointments created using those rules
– DST 2007, and the appointments we talk about are those occurring in the “extended” DST 2007 period, which as you may know by now is the period between March 11-April 1, because we’re moving clocks forward by an hour 3 weeks earlier than usual, and between Oct. 28-Nov. 4 2007 – because we’re moving clocks back by an hour a week later than usual. Let’s refer to these as the affected appointments.

1. User workstation gets KB 931836: This updates the time zone definitions in the operating system’s registry. It changes *when* the computer will switch to Daylight Savings Time, and when it’ll switch back. Now, all those old appointments in the affected period appear an hour later. These are the appointments we need to rebase.
(Computers with old DST 2006 time zone, i.e. ones without KB 931836 update applied, will still show these at the correct times).

2. Appointments created while the KB 931836 time zone is applied (and occur during the affected period): These appointments will appear correctly. NO REBASING REQUIRED.

3. Appointments rebased using the Outlook Calendar Update Tool or the Exchange Calendar Update Tool. What this does – changes the Start and End times – which are in UTC/GMT (again, covered in previous post)

4. On computers with KB 931836 applied:
– Old appointments rebased, show up at the correct time
– If new appointments rebased wrongly, these show up one hour early

On computers without KB 931836 applied
– Old appointments rebased, show up an hour early in Outlook
– New appointments (if) wrongly rebased, show up two hours early

Regardless of when rebasing is done, recurring items do not get rebased wrongly. These have the time zone embedded in the item which prevents them from being wrongly rebased by any of the rebasing tools.

Also note, appointments rebased once will not get rebased again when you run either tool.

{ 2 comments… read them below or add one }

Somebody's Mom, Daughter, Sister and Wife March 7, 2007 at 5:04 pm

I am having the most difficult time with the rebasing. My patches have been applied to both the client and the servers. The rebase tool will not open the mailboxes no matter what I change – I continue to get the legacyDN error 80004005, I change the .ini file to reflect my environment and the tool changes it back to the incorrect DN ; however it finds the mailboxes. Then when trying to access the mailboxes it errors out.

So I ran the tzmove tool on my computer to see what it would do – it moved my “recurring appointments” that I made, but of course not the appointments that someone else put on my calendar.

Here is what I don’t completely understand….if my server is up-to-date and all the mailboxes reside on the server – what is the need for the rebase tool. Also at this late date what do I do to correct my issues??? Over half of my users are using OWA exclusively – this is a problem that I cannot be alone in and am grasping for help.


Bharat Suneja March 7, 2007 at 5:28 pm

The rebasing tools will only move the appointments that you’ve organized. Appointments/meetings created/organized by other users will be rebased when their mailbox is rebased – you should get meeting updates when that happens.

The need to rebase is explained in previous post: “DST 2007: Understanding what needs to be done and how to do it


Leave a Comment

Previous post:

Next post: