Explanation
Data validation rules are triggered when a user adds or changes a cell value.
The AND function takes multiple arguments (logicals) and returns TRUE only when all arguments return TRUE.
The DATE function creates a proper Excel date with given year, month, and day values.
If either condition is FALSE, AND returns FALSE and input fails data validation.
AND returns TRUEonly if all the conditions are met.
If any conditions are not met, the AND function returns FALSE.
