Personally, I'd go with your world's original calendar, since that would be marking your age properly.
But I'm also used to thinking as someone who'd have to go to other worlds on a regular basis. In this specific situation, it probably wouldn't matter too much which way you choose as long as you're consistent about it.
no subject
But I'm also used to thinking as someone who'd have to go to other worlds on a regular basis. In this specific situation, it probably wouldn't matter too much which way you choose as long as you're consistent about it.