thanks all for making things clear here.
i started the discussion about it yesterday in our dev-chat
the reason behind this question is that i want to make a combat log export, like wow logs, and for this all timestamps from all players (for e.g. in group) have to be in sync. otherwise you'll have an offset.
i think i have to add a datasync before the fight starts, to get all players in sync :/ i hoped that i don't have to