Exception calling when TimeZoneInfo.ConvertTimeToUtc for certain DateTime values

Question

When I run the code for this specific value of dt, an exception is thrown when I call the ConvertTimeToUtc Method. My local Machine timeZoneId is \"GMT Standard Time\"

Answer 1

One can test whether the time in question is invalid using

TimeZoneInfo.IsInvalidTime

or if it is ambiguous using

TimeZoneInfo.IsAmbiguousTime

If it is ambiguous, an array of times that could apply can be retrieved from

TimeZoneInfo GetAmbiguousTimeOffsets

In the case of an interactive application, the user can be prompted for clarification.

The BCL team wrote a good blog about the topic

https://docs.microsoft.com/en-au/archive/blogs/bclteam/system-timezoneinfo-working-with-ambiguous-and-invalid-points-in-time-josh-free