CalDAV records generated by emClient incorrectly address daylight savings time

Hello. I am using emClient 3.5.12280.0 as a CalDAV client and Smartermail 9 for my CalDAV server. I noticed events were an hour off when sycnhronizing with my Android phone’s calendar using CalDAV-Sync. I have Smartermail and clients set to America/Chicago (UTC-6, Central time Zone).

CalDAV-Sync’s developer kindly reviewed my CalDAV records, and discovered that emClient may be generating CalDAV records incorrectly with respect to daylight savings time. He called the suspect items “Olson IDs”.

Events created on my phone and on Smartermail’s calendar web GUI sync properly to all devices. Only events generated within emClient have this problem.

Looking at the records, emClient contains this:




which seems to signify that standard and daylight savings time begin on the same date. In contrast, the Google calendar handles it this way:




Is this assessment correct, and can emClient address a fix? Many thanks and credit to Marten Gajda at CalDAV-Sync.

This really seems like a bug - is there a way to make sure this post is seen by the emClient folks? I am free user so this forum is my only suport recourse of which I am aware. Thanks!

Please try the hotfix from Microsoft:

Thanks, but the problem is not with the Windows clock, it is with how emClient generates calDAV records that involve daylight savings time. See first post.

thank you and Mr. Gajda for the analysis. I understand the problem with DSTARTs that the analysis suggests, although all clients and servers so far have been able to cope with it. Anyway, we will try to address the issue and create appropriate DTSTART values when generating the timezones.


Best Regards,
Libor Grafnetr

Thanks very much Libor.

I did. And how do you think eM get the time in Windows? I only post that because this error was cover in the forum before, and some users has report back that it solved the daylight saving time error for their calendar.

It will only cost you less than 5min to try.

Tried, it says “the update is not applicable to your computer”. I’m on fuly updated Win7. Apologies if I missed where the CalDAV DTSTART for DAYLIGHT and STANDARD has been discussed before, if you could please point me to the threads. Thanks!