This time stuff has been gnawing on my brain for years, as a fiction writer. In my writing I have beings that were born in different parts of the galaxy, some born on things that weren’t even planets or near a star, so I have a hard time trying to put forth how old they are, except to say they are ancient or ageless or something vague like that. If I try to put a number of years on them I immediately think “okay well they aren’t from earth nor are they on earth, so what exactly is a year in this context”. I have yet to settle on a solution.