What HTTP status should be given to the client in case of an error in validation?

Question

Django

Hello! Such a question, I have a site for creating classes for different groups, I create them with Ajax, it is possible to create two classes on the same day and at the same time, but provided that one of them is for even weeks and the second for odd weeks, I throw a validation error and status code 412, is this the right solution in my situation? If not, what status should I give to the client?
Thanks in advance!

Answer 1

400