Date validations

I’m looking for some experienced assessments of how / whether I need to bother to validate dates in my Rails app. I’ve Googled the topic but what I’m finding doesn’t tell me what I want to know.

I’m not concerned with visitors entering invalid dates while they’re using my app. All dates are entered via selects. Also, the app doesn’t contain any date processing / calculations.

What I’m looking to guard against is hackers who might try to corrupt the database using a means of access other than the app. I’ve got length and format validations on all the string fields, and numericality validations on all the int fields. But I can’t get my arms around how or even if I need to validate the date / datetime fields. Again, I don’t care if whatever they might try to feed the db (MySQL) gets turned into 0000-00-00 or whatever. I just want to ensure that they’re not able to corrupt the db, create a buffer overrun, etc.

Thanks much for any advice.

Best regards,