The difference should be handled at the same layer as time zones, which is already a mess and is already well-suited to deal with this type of thing. I'd argue

The difference should be handled at the same layer as time zones, which is already a mess and is already well-suited to deal with this type of thing. I'd argue there should be no adjustment until it gets to be +- 15 minutes from UT1. And even then, NO clock skewing, just a time zone adjustment across the board.