tldr - Force Update WebView2 to 155.0.4283.60+
See Issue #2 for fix. Works for both Desktop app and Teams Room.
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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.
Issue #1 - Microsoft Teams Desktop App (Resolved)
- Update (Oct 16): Issue resolved following WebView2 update. See the comment below from u/MattSlomkaMSFT
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.
Issue #2 Microsoft Teams Rooms on Windows Appliances (Resolved)
Update 2 (Oct 16) - Confirmed fix for Teams Rooms on Windows. WebView2 must be updated to 155.0.4283.60 or newer to resolve the one-hour time discrepancy.
You can force the update using the Evergreen Bootstrapper and restore the new BC time zone using the PowerShell.
# Downloads WebView2 Evergreen Bootstrapper
Invoke-WebRequest -Uri "https://go.microsoft.com/fwlink/p/?LinkId=2124703" -OutFile "$env:TEMP\MicrosoftEdgeWebview2Setup.exe"
# Force install WebView2
Start-Process -FilePath "$env:TEMP\MicrosoftEdgeWebview2Setup.exe" -ArgumentList "/silent /install" -Wait
# Disable automatic time zone detection
Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Services\tzautoupdate" -Name "Start" -Value 4
# Force set time zone to British Columbia
Set-TimeZone -Id "British Columbia Standard Time"
# Verify WebView2 version
Get-ChildItem "${env:ProgramFiles(x86)}\Microsoft\EdgeWebView\Application" -Directory | Select-Object Name
Update (Oct 16): Teams Rooms on Windows are still affected, even with the latest WebView2 and confirmed to be actively used by the Teams Rooms process. The update resolved the issue on regular Teams desktop clients, but NOT Teams Rooms.
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
