When you want to know the number of days between two dates whether the date is in the future or the past, you can use Excel to calculate it.

The DAYS function in Microsoft Excel returns the number of days between two dates. The formula for the DAYS (end_date, start_date).

You already knew that Excel can do straight date math, but it can also take into account holidays to find the number of working days between two dates.

Click the drop-down arrow in this area and choose either of the two "Date" options. The long number in the cell with transform a date, which will be the midpoint between your two given dates.