While breeders advertised times have to be taken with a grain of salt, it does give an bench mark guide...you'd think a breeder probably has an optimum grow area for the best seed producers and we all know environment control changes things.
As MOG says, it's rare but I've seen a below 60 days finish perhaps twice in 15 yrs.
When my wake up jar gets low, I'll take a nug or two early anyway.