Returns the number of weeks between two dates.
This function is only available if the Analysis AddIn is installed.
WEEKS(startdate; enddate; mode)
WEEKS("2010-05-03"; "2010-05-17"; 0)
WEEKS("2010-05-04"; "2010-05-27"; 0)
WEEKS("2010-05-06"; "2010-05-17"; 1)
WEEKS("2010-05-09"; "2010-05-10"; 1)