Depends on the magic. Fireball was used in the seventh through fourteenth centuries, so that's not anachronistic. But if you want to do elemental transmutation, that wasn't discovered until 1896. You could have it in steampunk.

Fair point! I'm not saying it's a bad thing, it's just interesting to me cause I'm not used to it. I usually run D&D as medieval (like ~1300 AD) European fantasy with magic and a little bit of anachronistic renaissance stuff.