September 2025 Calendar Missing Days Excel. The networkdays function returns the number of whole working days between a start_date and end_date. You can add or subtract a number of days to or from a date by using a simple formula, or you can use worksheet functions that are designed to work specifically with dates in excel.

The syntax for the function is “=days (end_date, start_date).” You can easily do this using formulas such as datedif or yearfrac