DAYS360

Microsoft Office Excel 2003

See Also

Returns the number of days between two dates based on a 360-day year (twelve 30-day months), which is used in some accounting calculations. Use this function to help compute payments if your accounting system is based on twelve 30-day months.

Syntax

DAYS360(start_date,end_date,method)

Start_date    and end_date are the two dates between which you want to know the number of days. If start_date occurs after end_date, DAYS360 returns a negative number. Dates should be entered by using the DATE function, or as results of other formulas or functions. For example, use DATE(2008,5,23) for the 23rd day of May, 2008. Problems can occur if dates are entered as text.

Method    is a logical value that specifies whether to use the U.S. or European method in the calculation.

Method Defined
FALSE or omitted U.S. (NASD) method. If the starting date is the 31st of a month, it becomes equal to the 30th of the same month. If the ending date is the 31st of a month and the starting date is earlier than the 30th of a month, the ending date becomes equal to the 1st of the next month; otherwise the ending date becomes equal to the 30th of the same month.
TRUE European method. Starting dates and ending dates that occur on the 31st of a month become equal to the 30th of the same month.
Remark

Microsoft Excel stores dates as sequential serial numbers so they can be used in calculations. By default, January 1, 1900 is serial number 1, and January 1, 2008 is serial number 39448 because it is 39,448 days after January 1, 1900. Microsoft Excel for the Macintosh uses a different date system as its default.

Example

The example may be easier to understand if you copy it to a blank worksheet.

ShowHow?

  1. Create a blank workbook or worksheet.
  2. Select the example in the Help topic. Do not select the row or column headers.

    Selecting an example from Help

    Selecting an example from Help

  3. Press CTRL+C.
  4. In the worksheet, select cell A1, and press CTRL+V.
  5. To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Tools menu, point to Formula Auditing, and then click Formula Auditing Mode.
 
1
2
3
A
Dates
1/30/2008
2/1/2008
Formula Description (Result)
=DAYS360(A2,A3) Number of days between the two dates above, based on a 360-day year (1)