Longer Breeding Intervalls in the Cattery?

[Malicia Python]

When I had my cats inworld - some ago, they had a box exactly after 7 days usually to the hour. I noticed a slightly longer span in the cattery. Maybe just a few hours each week but the same couple that used to breed on a Monday is like Wednesday in the end of their breeding life.
I wondered if inworld cats needed a bit longer, compared to before the online cattery was introduced or if it is a cattery specific thing.
Puzzeled regards Mal