Returns the number of days between two dates, based on a 360-day calendar.
days360( start_date, end_date, method )
start_date: (Date) The starting date.
end_date: (Date) The ending date.
method: (Integer) 1 for European, 0 for US/NASD.
Integer
days360(today(), today() + 365, 0)
returns 360