Expiration Date with Edate accounting for leap years

Using excel to indicate expiration dates by X # of months form the date of manufacture, but it does not accurately account for leap years.

Formula is =EDATE(G3,18) (Where G3 is the manufacture date, and we want to add 18 months to get expiry). This usually works, however....

March 30 2021 should yield an Expiry of Sept 30 2021 - which works with the EDATE function above.

March 31 2021 should yield an Expiry of Oct 1 2021 (leap year!) - BUT it doesn't! It still yields Sept 30 2021 (so short 1 day)

What am I doing wrong? Or how do we account for leap years when calculating expiration?