The result is a date which is a number of months away from the start date. Only months are considered; days are not used for calculation.
Months 是指開始日期之前 (負值) 或之後 (正值) 的月數。
What date is one month prior to 2001-03-31?
=EDATE("2001-03-31";-1) returns the serial number 36950. Formatted as a date, this is 2001-02-28.