Pretty sure this is a bug so I'm posting here.

If you start a BDS server and somehow check the in-game time without logging in to the server (NBT Editor etc) take a note of the time. Check after some time it will be the same (Expected)

Login to the server, then logout. check time. Check again after some time again and time has continued to pass even with no players online. This is commonly noticed when you logout in the day and it's night when you go back on.

Expected: time should stop progressing when the last member logs off