DAYS_360

Syntax:

DAYS_360(start:date, end:date {, method:number})

This function returns the number of days between the given dates according to the desired 360-day calendar method.

Credit: http://en.wikipedia.org/wiki/360-day_calendar

A duration is calculated as an integral number of days between two dates A and B (where by convention A is earlier than B).

There are two methods commonly available which differ in the way that they handle the cases where the months are not 30 days long:

In both cases the difference between the possibly-adjusted dates is then computed by treating all intervening months as being 30 days long.

Added in 1.36.