Birthdays on calendars reset after update

I haven't had that drastic of a reset, but I've had my sims occasionally have their birthdays moved to the next day for no reason. Like it will be my sims birthday and they'll just never automatically age up. 

@frogcandlespretty sure it's by design that if you ignore the "it's ____'s birthday!" notification you'll get a day or two before the age up is forced - giving you time to try to have a party or get a de-aging potion, and pushing back the birthday so that it's still "today" until you age them up or they do so automatically. Also, Sims that are pregnant won't age. So each day your Sim is pregnant, you'll see their birthday move out a day.

@Sheli38I don't think teen life spans changed, but some of the other life stages have expanded. Maybe they adjusted where the teen was to make it match up better with other expanded life stages? On long life span with 7 days until adult, your Sim would have spent 4 as a baby, 28 as a toddler, 52 as a kid, and what... 77 as a teen? Or did that used to be shorter?

But now there's an additional 20 days as an infant, and they added another 4 days to child... did they age back those 24 days? Did teen used to be shorter than 84 days?

I haven't opened any existing saves yet, nor do I honestly remember how close my Sims were to their birthdays. So I can't really test how any of these expansions translate.

Thanks I think you’re right and it’s definetly the new life stages that have altered the current ages/birthdays. I wish they’d include that tweak in the base game patch update communication. It’s a bit annoying if you’re trying to track when they should be ageing up. I know it’s not the worst problem but still a bit annoying.

Thanks for your help.