Working with Excel validation

Data validation is a feature in Microsoft Excel used to control what a user can enter in a cell of a worksheet. It can restrict entries to a specific date range, whole numbers only, or even create drop‑down lists that save space and display values in a single cell. You can also define a custom message that appears when a user enters an incorrect value or an invalid format.

For example, a user can specify a meeting scheduled between 9:00 AM and 6:00 PM.

Data validation can be used to ensure a value is a positive number, a date between the 15th and 30th of a month, a date occurring within the next 30 days, or a text entry containing fewer than 25 characters, etc.

Working with validations on an Excel file