MS Outlook incorrectly interprets ICS files in local time: daylight saving time overshoot

Question

Does anyone know a way in the ICS file to indicate what is written all the time at local time in this place? I thought that I should leave “Z” over time, and using TZID = “America / Denver” (for example) in the DTSTART and DTEND lines, this did, but MS Outlook assumes that it is in a standard location all the time. My activities take into account daylight saving time.

Do I need to rewrite the application, so is the time in UTC?

Should I include a block at the beginning that defines any time zone? This is complicated since I want to maintain every time zone in the Olson database.

But at present, MS Outlook is pushing every appointment to the fact that during daylight saving time, one hour in advance, which is wrong.

Thanks in advance for your help.

Answer 1

I had a very similar problem, and I researched a lot, but the solution is still not the best. I'm not sure why Outlook does not handle local times correctly; it makes scheduling local time assignments for other time zones a big problem. The standard clearly indicates that if the time zone is not specified and the UTC 'Z' symbol is not used, then the time should be the same regardless of what time zone the receiver is in. However, Outlook does not adhere to this and changes the time depending on the time of sending the client and the time of receiving the client.

In my case, I have a website that allows certain users to schedule other users for meetings. These users can be located in many different time zones. Fortunately for me, the site is specifically located in one time zone. So my solution was to write a simple C # switch statement that shifts the time based on where the receiving user is relative to where the server is. I do not specify the time zone in the .ics file, and I do not mark the time as UTC with the “Z” character.