@shanls96 Yes, those numbers are the exact number of days for the life stage IF you are playing with normal lifespans. If you play with short or long lifespans, it's a factor of those days instead ( 1/2 if you select short, x4 if you select long).
If you want lifespans that are the game defaults, just change them in MCCC and click the 'default' button. I have them set just a little under double normal, because I feel normal is too short, but LONG is waaaay too long.
I set them where my sims have enough time to actually have a social life and still get near the top of a career ladder before having children. And allow for them to be able to fully raise a few kids before they became elders. For my personal style of play, those settings are such that my sim's are usually turning elders shortly before their kids are having kids, making it perfect for me.