Explanation
Data validation rules are triggered when a user adds or changes a cell value.
The TODAY function takes no arguments.
you’re able to format the value returned by TODAY with a datenumber format.
If you need current date and time, use…
Data validation date in specific year
Note: Excel has several built-in data validation rules for dates. This page explains how to create a your own validation rule based on a custom formula in case you want or need more control and flexibility. To allow a user to enter only dates in a certain year, you can use data validation with a custom formula based on the YEAR function. In the example shown, the data validation applied to C5:C7 is: =YEAR(C5)=2016
