Auto Complete rule for Validating Last working day field

Summary:

Whenever A employee submits the resignation then we want to have a valiation to check if LWD date is Less than Todays date plus 5 days then throw error.

Content (please ensure you mask any confidential information):

If Employee submits resignation and When is your Last Working Date (LWD)? field is less than or equal to Todays date plus 5 days then throw error.

Is it feasible? If yes can we get the sample rule.