How do you know when it is a sims birthday?

Answer 1

when your in gameplay, you click on the picture of the plumbob (the diamond thing, it says simology when you hover over it) when you click that you should see an icon for their family tree at the top, then a bar that fills in with green as your sims get older, and their favorites at the bottom of that. when the bar fills all the way with green, its your sims birthday! (when you hover over the bar it will tell you how many days they have left before they grow up) the game tells you when your sim had two days before their birthday and they tell you to grow them up two or three days early

Answer 2

A box pops up and says that your sim is turning to toddler,child,teen,adlut,and/or elder at 6:00 p.m.