Spreadsheet Practice

How to check if a cell contains a date in Excel

Formula (Excel and Google Sheets)

=ISNUMBER(A2)

Real dates are numbers, so =ISNUMBER(A2) is TRUE for a date and FALSE for text that only looks like one.

Result on the example
one result per row in B2, filled down to B7
Works in
Every current version
Google Sheets
Same formula

See it work

The formula is already in B2, filled down to B7. Change any input and the result updates, or edit the formula to experiment.

How it works

Spreadsheets store real dates as numbers, so ISNUMBER is TRUE for them and FALSE for text that only looks like a date, such as "3/9/2026" imported as text, or an impossible date like "2026-13-01".

=ISNUMBER(A2)

ResultTRUE

  1. A23/5/2026

    The value in A2.

  2. ISNUMBER(A2)TRUE

    ISNUMBER: TRUE if the value is a number.

    • valueA23/5/2026

In Google Sheets

The same formula works in Google Sheets: =ISNUMBER(A2). We ran it in Google Sheets mode on the same data and it returns the same results.

Other ways to do it

Each one was run on the same example sheet.

FormulaResultWhen to use it
=IF(ISNUMBER(A2),"Date","Not a date")Date, Not a date, Date…Different resultA readable label. Shows Date or Not a date.
=AND(ISNUMBER(A2),A2>=DATE(2000,1,1),A2<=DATE(2100,12,31))TRUE, FALSE, TRUE…Also rejects numbers that are too small or large to be dates in your data, like 42.

Common mistakes

  • Any number passes ISNUMBER, including 42 or a price. Add a range check when the column can hold other numbers.
  • Excel has no ISDATE function. CELL("format",A2) returns a code starting with "D" for date-formatted cells, but it checks only the format, not the value.

Try it yourself

Same data, empty answer cell. Your formula is graded instantly, then re-checked on changed data, so a typed-in number won't pass.

Check if a cell contains a date

In B2, return TRUE if A2 holds a real date and FALSE if it holds text, and fill down to B7.

Questions

How do I convert the text dates?

=IF(ISNUMBER(A2),A2,DATEVALUE(A2)).

How do I highlight cells that aren't real dates?

Use conditional formatting with the rule =NOT(ISNUMBER($A2)).

Checked by running on 2026-10-30: every formula and result on this page was calculated by the Spreadsheet Practice formula engine, in both Excel and Google Sheets modes.