Clock change on SQL Server
SQL Server just uses the operating system's time. However, if your application code relies on functions like GETDATE(), then your code needs to be able to handle jumps forward (or backward) in time.

For example, if your have code that does something like this:

SET @StartDate = GETDATE()
(Do some work)
IF DATEDIFF(MM, @StartDate, GETDATE()) &gt; 60 ....


That code can fail. Long term, consider using GETUTCDATE() instead and storing dates with DATETIMEOFFSET - but that's a big code change that you can't really do quickly before changing the date on a server.