The Excel DAY Function

Function Description

The Excel DAY function returns an integer representing the day of the month (from 1 - 31) of a supplied date.

The syntax of the function is:

DAY( serial_number )

where the serial_number argument is the date that you want to return the day of.

Note that it is recommended that dates should be supplied to Excel functions as either:

or or

If you attempt to input dates as text, there is a risk that Excel may misinterpret them, due to different date systems, or date interpretation settings on your computer.

Day Function Examples

Column B of the following spreadsheet shows the Excel Day function, used to extract the day from three different dates.

  A B
1 31-May-2015 =DAY( A1 )
2 21-Mar-1984 =DAY( A2 )
3   =DAY( DATE(2016, 1, 1) )
  A B
1 31-May-2015 31
2 21-Mar-1984 21
3   1

Note that, in the above examples:

For further examples of the Excel Day function, see the Microsoft Office website.

Excel Day Function Common Problem

Common Problem:

The result of your Excel Day function looks like a date (e.g. "01/01/1900"), instead of an integer.


This problem is most likely to be because the new cell or column is formatted as a 'date'. In this case, it is only the formatting of the cell that is wrong, NOT the value returned by the function.

The easiest way to do correct this is to select the General formatting option from the drop-down format menu of the Excel ribbon. This is generally located in the 'Number' group, on the Home tab of the ribbon (see below):

Excel Format Cells Drop Down Menu on Ribbon With General Option Selected

See the Excel Formatting page for more information on formatting in Excel.