DAY

What does the DAY function do?

The DAY function returns the day of the month from a given date. The result is always a number between 1 and 31.

Examples:

• =DAY(“2025-06-17”) → 17
• =DAY(A2) → if A2 contains 01/01/2024, result will be 1

This function is useful when you need to group or filter data by day of month, for example – to find all events that occurred on the “first day” of any month.

Formatting

DAY() returns an integer that can be immediately used in calculations, filtering, or visualization. No additional formatting is required.

If the result displays as a date, simply change the cell format to “General” or “Number” (Ctrl+1 → Number).

Syntax

=DAY(date)

Date is the only required argument. It can be:

• reference to a cell containing a date (A1);
• result of another function (TODAY(), DATE(2025,1,1));
• text string with a date (e.g., “2025-01-01”), though this is not recommended.

Usage examples

=DAY(A2)

=DAY(TODAY())

=DAY("2025-12-31")

Practical applications

• Calculate due dates based on day of month
• Filter transaction data by specific days
• Generate monthly reports grouped by day
• Calculate age in days from birth dates
• Track project milestones by day

Features

• The DAY function returns only the day number of the month, regardless of the date display format
• If the argument is unrecognizable text, Excel returns #VALUE! error
• If an empty cell is passed, the result is 0
• Works with dates from January 1, 1900 to December 31, 9999
• Returns values from 1 to 31 (depending on the month and year)

Combining with other date functions

The DAY function is often used with MONTH and YEAR to extract all date components:

=DAY(A1) & "/" & MONTH(A1) & "/" & YEAR(A1)

Other Date and Time functions in Excel

TIMEVALUE, TIME, YEAR, DATE, DATEVALUE, EDATE, WEEKDAY, YEARFRAC, EOMONTH, MONTH, MINUTE, WEEKNUM and WEEKNUM.ISO, WORKDAY, DATEDIF, TODAY, SECOND, NOW, HOUR, NETWORKDAYS

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