Hi Bren! (simsane's smiling and waving at you!) Okay, I checked with a bunch of them, but I'll list 4 here:

Fate 24 years old yesterday at 11:00 a.m. and 30 years old today at 11:00 a.m. So, she aged 6 years in 24 hours, which is 1 year for every four hours real time.

Logory and Katetta were both 45 years old yesterday at 11:05 a.m. and were both 51 at 11:04 a.m. Again, 1 year for every four hours.

Vanilla was 7 yesterday at 11:08 a.m. and she is now 13. Same thing -- she has aged 6 years in 24 hours, so 1 year for every four hours.

I know that they do go from birth to 2 in about 4 hours, but I think after that it requires 4 hours for one year. Actually, I'm glad it's not 1 year for every two hours or else we would barely be able to play them before they died.