By: PF

Your three methods don’t produce the same result if the initial year is before a leap year and the date is after 2/28. For example, if the date is 2011-3-1, here are the results:

method #1: 2012-02-29
method #2: 2012-03-01
method #3: 2012-03-01

EDATE(startDate, month-offset) and DATE(y, m, d) take leap years into account. Simply adding 365 days to a date (method #1) assumes that all years are 365 days long.

If your desired result is to maintain the day after adding x number of years, you cannot use method #1. Most people and institutions (banking, due dates on payments, etc.) would assume that adding x number of years takes into account leap years.

I suggest you edit this webpage to add a caveat to method #1, or remove the method entirely.