So Lore wise, I just sort of tie it in with FFXIV's already made history. I tied this job with the Astrolagians since they have some connections with time.
The job components I searched Final Fantasy Jobs, and it gives you a break down to jobs used in previous games. I add some FF Classic moves with some new ones. Its interesting to read where the jobs appear and their moves, and corresponding moves that are constant game after game. Time Mage is very interesting, as it can be a fun little job to play with, and whatever way its sliced would be super interesting how it would pan out.
But Lore is all about the imagination, just make a story, flesh it out, and show it. That's what I do with all my job concepts, the story sometimes is the most important part as it breaths life into the job your making.
I tied in my Rune Fencer with Red Mage in one of my previous concepts, bc I love how Astrolagians tied Geomancer in with their story; so I can't wait to see if we can get play as Geomancer in the near future.