Add a validator on PeriodMixin itself, raising validation error if the dates overlaps.

[shreyansh23]

[dhruvkb]

Django does not support model validation on two fields. The most that can be done as of now is to create a function validate_dates() that you would have to call manually by overriding save() in your model class.

Would that solve or mitigate your issue?

[shreyansh23]

Yes, that will work fine!