I'm wondering whether this is a known Teams compatibility issue or if a minimum Teams/Teams Rooms application version is required to support the new time-zone definition.

Sharing our findings since I haven't been able to find much information about this yet.

Following Microsoft's recent Windows update introducing British Columbia Standard Time (UTC-07:00), aka PCT, we've identified two issues affecting Microsoft Teams.

The key finding is that these issues only occur when Windows is set to the new British Columbia Standard Time. Windows itself displays the correct time, but Teams appears to interpret the new time zone incorrectly.

Microsoft Teams Desktop App (Windows 11)

• Windows is configured with British Columbia Standard Time.
• Windows system clock correctly displays local time (UTC-07:00).
• Teams chat message timestamps are 1-hour behind. For example, a message sent at 2:55 PM shows as 1:55 PM in Teams.
• Teams calendar display meeting times correctly, regardless of whether the events were created using the traditional Pacific Time (PST) or the new BC Pacific Time (PCT) time zone.

Microsoft Teams Rooms on Windows (Windows 11 IoT Appliances)

On our MTR appliances with the new BC time zone:

• The Teams Rooms interface clock displays one hour behind the actual local time.
• Scheduled meeting start and end times are also displayed one hour behind.
• Windows 11 IoT itself shows the correct time and UTC-07:00 offset.
• Teams Rooms on Android are not affected.

Exchange Online Time Zone Settings Have No Effect

Teams Rooms resource mailboxes were originally set to Pacific Standard Time. Updating them to British Columbia Standard Time had no effect on the Teams Rooms clock or meeting times. We also tested Arizona and Yukon time zones with the same result.

Windows Time Zone

Running Get-TimeZone returns:

Id                         : British Columbia Standard Time
DisplayName                : (UTC-07:00) Pacific Time (British Columbia)
StandardName               : British Columbia Standard Time
DaylightName               : British Columbia Daylight Time
BaseUtcOffset              : -08:00:00
SupportsDaylightSavingTime : True

My suspicion is that certain Teams components may be interpreting the base UTC offset (-08:00) instead of the effective offset (-07:00), resulting in the one-hour discrepancy.

The new British Columbia Standard Time uses a base UTC offset of -08:00, with DST adjustment rules bringing the effective offset to -07:00.

$tz.GetUtcOffset([datetime]"2026-10-15").ToString()
-07:00:00
$tz.GetUtcOffset([datetime]"2026-11-15").ToString()
-07:00:00

I want to have a channel meeting.

Why:

- avoid creating a new chat in sidebar for just that meeting series or occurrence.

- still have a functional "chat" in the meeting itself (our team is accustomed to using this - it's great - we don't want to get lost looking through other things during a meeting)

Problem: a channel meeting includes [myteam@myco.com](mailto:myteam@myco.com) on the invite list, which causes the meeting to get added to everyones calendar. (Even though I only added a few people as required on the meeting, everyone started joining)

Solution? Idk, what does the "Send personal invites" feature actually do?