The Excel DAY function, when supplied with a date, returns an integer representing the day of the month (from 1 – 31).
Syntax: DAY( date )
where the date argument can be supplied to the function as either a date returned from another formula or function or a references to a cell containing a date.
Warning: If you attempt to input the date argument as text, there is a chance that Excel may misinterpret this, depending on the date system, or date interpretation settings on your computer. Also note that, although you can input the date argument as a serial number, this is not recommended, as the serial numbering may vary across different computer systems.
Day Function Examples
The following example shows the Excel Day function used on 3 different dates.
Note that, in the above examples, as recommended by Microsoft, the date value is always supplied as either a reference to a cell containing a date, or as a value returned from another function.
Excel Day Function Common Problem
The result of your Excel Day function looks like a date (eg. “01/01/1900”), instead of returning an integer.
This problem arises 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.
To correct this,
- Highlight the cell(s) with the wrong formatting
- Right click with the mouse
- Select the Format Cells … option and ensure the Number tab is selected
- Under the Category heading, select the option General and click OK