Using the Excel DAYS360 Function


When using the DAYS360 function in Excel you will be able to calculate the number of days between two dates based on a 360-day year. The twelve months each with 30 days format is used in some accounting calculations. This function can be used to calculate payments if your company uses a 360-day year.


=DAYS360 (start_date, end_date, [method])

Syntax Breakdown

A date that represents the starting date in your function.

It is advised to enter dates using the DATE function to avoid issues that may arise from using dates that are formatted as text. Alternatively, you can also use dates that are derived from other formulas or functions.

Excel DAYS360 Date Entry

The date that will be the ending date for your function.

The method input is optional. This is for users who wish to specify if the United States or European method should be used in the calculation.

To select the U.S. method you can leave the parameter blank or enter FALSE. The U.S. method forces the starting date to equal the 30th day of the same month if the starting date is the last day in the month. It also forces the ending date to equal the 1st day of the following month should the ending date be on the last day of the month and the starting date is before the 30th day of a month.

If you desire to use the European method then enter TRUE. Using the European method will cause all starting and ending dates that occur on the 31st day to become equal to the 30th day of the same month.

Error Notes

Negative Output
If Start_date is after the End_date the function will return a negative number.

Excel DAYS360 Negative Result