powershelltimezoneutc

How to convert any timestamp of a given timezones into UTC?

I need a function that converts any given timestamp in a given TimeZone into UTC. I started by using the UTC-Offset of the source-timezone, but then it turns out, that this is not always correct because it does not respect the indiviual offset including/excluding the daylight saving time (DST) offset. The problem here is the fact, that DST starts/ends at different dates for many timezones. How can I fix that so that it works on any timestamp and for any timezone?

Here the initial Powershell code I made without respecting the daylight saving time:

$sourceTime = [datetime]::new(2024,3,12,10,0,0)
$sourceZone = 'Pacific Standard Time'
$utcOffset  = (Get-TimeZone -Id $sourceZone).BaseUtcOffset
write-host 'UTC-time:' ($sourceTime - $utcOffset)
Solution

  • Use the TimeZoneInfo.ConvertTimeToUtc method.

    But you should be aware that a value expressed as a local date/time might be invalid or ambiguous due to DST changes. (A value of 2024-03-10T02:30 for Pacific Time would be invalid, for example, because the clocks went forward from 2am to 3am.) You can detect this with the IsAmbiguousTime and IsInvalidTime methods.