The EOMONTH function is a useful Excel function to know. The purpose of it is to easily identify the last date of a specified month. The formula for this is EOMONTH(start date, how many months before/after). If the month you are looking for is in the future, the second part of the formula should be positive, or negative if it is in the past. For example, if you enter the date 12/04/2021 in cell B1 and use the formula =EOMONTH(B1,2), you will get the result 30/06/2021, as the end of the month, two months from the start date. Our example below shows EOMONTH in use for a various number of months in the past and future.
See the following article for more information: