Explanation

The EOMONTH function returns the last day of a month based on a given date.

In the example shown, months is supplied as -2, which causes EOMONTH to return 4/30/2015.

Then, 1 day is added to get 5/1/2015.

Excel formula: Get first day of month

Use a positive value for months to move forward in time, and a negative number…

Excel formula: Get last day of month

Excel EOMONTH function