Is it possible to validate Element Entry Start Date and End Date using Element Input Validation FF

We have business requirement to make user to enter Element entry Start Date and End Date of on element as per the business rule,
To achieve this we are trying ‘Element Input Validation Fast formula’ to restrict user from entering wrong Element entry Start Date and End Date.
But the validation is not working as intended.

So we want understand following,
1 Is it possible to validate the Element entry Start Date and End Date using Element Input Validation Fast formula?
2.If Yes, what is the Input values for Element entry Start Date and Element End Date?

Any inputs on this will help us.