Thanks for your bug report. The time features in v7.56 were updated to 1) use the Windows time APIs and 2) fix issues in v7.55 where it was not reporting correct values in some contexts.
That said, these changes were tested at the time, so I am not sure why the DST issue has appeared again. I remember that when v7.56 was being worked on, both I and others on the forums, tested it in different timezones and times of year, and it was returning the correct values.
I am going to make a change in the next beta and will test again in different timezones and times of year.
However, it will need further beta testing to confirm that it is resolved.