My game consists of multiple worlds that are connected by NRAAS Traveller.
There are two main worlds, Aurora Snows and Snows Haven, where my Sims live. Aurora Snows contains the university and the boarding schools and most of the families live in Snows Haven. The other connected worlds are travel destinations.
I play with aging off, but all of my Sims have a birthday that corresponds with their zodiac. I don’t have fixed dates, it is more like start of winter, middle of winter or end of winter, since I never know when I will play a Sims and I try to have them have their birthday when I play them.
I don’t age up the Sims to the next age stage on their birthday though, they only age one day.
So I age them up on their first birthday, I make a note in the biography of the toddler then, because since babies lifespans can’t be set lower than two days I skip one birthday for the toddlers to make the age right again.
Toddlers age to children on their 4th birthday.
Baby: 0-1 years old
Toddler: 1-4 years old
Children: 4-12 years old
Teenagers: 12-18 years old