Sims world is broken, time-wise. I went with one sim week being the equivalent of a year of sim age, based on University being able to be done in 4 weeks ... but time elsewhere was broken. A sim who entered college as soon as they became young adults was very likely to lose their parents to old age while they were in college. I haven't worked out the math on that since Growing Together changed life stage lengths, though.
I had worked out some new age durations based around that, but it was super not fun to play a few weeks as a toddler until they were old enough to go to grade school, then another 7-8 weeks as a child, six weeks as a teen, then like 22 weeks as a young adult and 25 weeks as an adult.
That was a compromise from wanting to do 4 seasons of 13 weeks each and having one year equal one year. My neurodivergence doesn't go as far as playing out a 364 day Sims year. As it was, after six weeks as a teen I was sick of my sim self by the time he was a young adult which, I guess, points for accuracy. And why was I even doing this? University isn't fun (points for accuracy), so I don't send my sims there as a rule.
I found a mod that reduces University length to one week, I'm back to using default lifespan, and if there's a particular NPC sim I wish would stay younger longer, I'll have a spellcaster whip up a rejuvenation potion to give to them.
