New Save has multiple versions

I opened a new save after the latest update and have noticed it seems to be saving differently now.

I have the original slot - 00000002.save                       then it has - save.day.ver0,   save.day.ver1  then it has - save.ver0   save.ver1, 2, 3, 4 like normal

Then it goes to 00000002.save.week.ver0

It is playing absolutely perfectly, no problems at all. Is this the way new saves will save from now on? None of my older saves have saved this way and I have played at least one since the update.

If yes, when I copy a save do I have to copy all the versions, not just the original plus the 4 versions like we used to do?

I hope this makes sense and that you can help me.