Investment Studio > Expressions > Functions > Date & Time > DAYS360
float days360(date start_date, date end_date, boolean european = FALSE)
Returns the number of days between start_date and end_date in a 360-day, 12-month financial year (often used in accounting calculations). If start_date occurs after end_date, the result is a negative number.
Automatic type conversion allows the use of date strings as arguments instead of explicit date values.
The european argument specifies the method used to handle dates that occur on the 31st of a month:
| Method | Interpretation |
| european = FALSE | US (NASD) method: If start_date is the 31st of a month, it's set to the 30th of the same month. If end_date is the 31st of a month, it's set to the 30th of the same month unless start_date is less than the 30th of a month, in which case end_date is set to the 1st of the next month. |
| european = TRUE | European method: Start and end dates that occur on the 31st of a month are set to the 30th of the same month. |
If european is omitted, it defaults to FALSE.
Note that the number of days between two dates in a normal year can be obtained with plain subtraction of date values.
Example
Assuming standard US date format settings,
=days360("1/30/1999", "2/1/1999")
equals 1, while
="2/1/1999" - "1/30/1999"
equals 2.
See also: networkdays, workday, yearfrac.