The DAYSINMONTH function returns the number of days in a month you specify.

For example, you can use DAYSINMONTH to check if a leap year occurs in February, so you can plan accordingly.

DAYSINMONTH(Year, Month)

ArgumentData typeDescription
YearNumberThe year that contains the month to determine the number of days within.
MonthNumber

The month to determine the number of days within.

Should be a number between 1 and 12 (the function returns a value of 0 for numbers outside this range).

The DAYSINMONTH function returns a numeric result.

DAYSINMONTH(2024, 2)

This example returns the number of days in February 2024. This is 29, as 2024 is a leap year.

The DAYSINMONTH function returns a value of zero for any values outside of the date range of 01/01/1900-12/31/2399.

EOMONTH

FormulaDescriptionResult
DAYSINMONTH(2023, 1)Returns the number of days in January 2023.31
DAYSINMONTH(2023, 2)Returns the number of days in February 2023.28
DAYSINMONTH(2024, 1)Returns the number of days in January 2024.31
DAYSINMONTH(2024, 2)Returns the number of days in February 2024.29