Formula to add X months to a date?
How can I add X months to an existing date in iWork Numbers?
=EDATE(start_date,months_after_start_date)
Start_Date can be a cell or a specific date. The number after the comma is the number of additional months.
For example, if 7/15/17 is in Cell A1 and you want Cell B1 to read 8/15/17 then you would use the formula: =EDATE(A1,1)