@mikey2262_NL If you mean when are transfer of players being done - there is no transfer "days" or somehing like that. Every day there is 8 different transfer windows in which players are being sold by random chance.
As for "transfer deadline day" per se, there is something related to that and it is called "transfer madness" which is special event in which instead of 4 players you can put 6 on the transfer list and during that event players are being sold much easier (even those valued more). There, I hope I managed to explain it well 🙂