I have had this doubt before, but I think now is the right time (pun intended) to ask the question. What criteria should I use to decide between the two tags? Are they mutually exclusive? Is it fine if I tag my questions with both if I am not able to find compelling arguments to exclude any of the two?
On examination, nobody had ever created guidance for either tag, so I understand the confusion here. Often we have near-duplicate tags which are created like this, which just need cleaned up when we find them.
Honestly I can't really see any difference between them, so I've merged them both into 'Chronology', and added a new Synonym so that if anybody tries to use Time again it'll get converted automatically. Feel free to add some guidance notes to it.
Thanks for highlighting!