Using the Excel EOMONTH Function
SummaryEOMONTH is an Excel function that returns the last date of the month that is N months before or after the indicated start date. The day is returned as a serial number, but can be formatted in a user friendly date format. The EOMONTH function is helpful when calculating payments that occur on the last day of the month. It's also useful with other functions, such as WORKDAY, that require the last day of the month for other calculations.
Syntax=EOMONTH (start_date, months)
Start_date is a required field that represents the starting date in your function. To avoid errors that may arise from entering dates as text, it is advised to enter dates using the DATE function or as the output of other functions or formulas.
Months is a required field and represents the number of months before or after start_date. Entering a positive number will return a future date and a negative input will return a past date.
Usage Notes#VALUE! Error
Excel stores dates as sequential serial numbers starting with January 1, 1900 (1) and ending December 31, 9999 (2958465). The #VALUE! error will be returned if start_date or start_date + months is not a valid date.
Excel will truncate the months value if the input is not an integer.