When does the Age of Rebellion era begin?

I’ve seen lots of conflicting info on what exactly marks the beginning of that era.

I’m between these events:

  1. Beginning of battle of scarif

  2. End of battle of scarif

  3. Beginning of battle of Yavin

  4. End of Battle of Yavin

Also I used to think rogue one took place in 0 BBY just like ANH but recent sources say rogue one takes place in 1 BBY while ANH (which takes place right after) is still set in 0 BBY. How does that make sense?