How to use the EOMONTH function

What is the EOMONTH function?

The EOMONTH function returns an Excel date for the last day of a given month using a number and a start date. Use EOMONTH to calculate maturity dates or due dates that fall on the last day of the month.

What is EOMONTH an abbreviation of?

EOMONTH stand for End Of month.

What are dates in Excel?

Dates are stored numerically but formatted to display in human-readable date/time formats, this enables Excel to do work with dates in calculations.

For example, dates are stored as sequential serial numbers with 1 being January 1, 1900 by default. The integer part (whole number) represents the date the decimal part represents the time.

This allows dates to easily be formatted to display in many date/time formats  like mm/dd/yyyy, dd/mm/yyyy and so on and still be part of calculations as long as the date is stored numerically in a cell.

You can try this yourself, type 10000 in a cell, press CTRL + 1 and change the cell's formatting to date, press with left mouse button on OK. The cell now shows 5/18/1927.

What is a maturity date?

The maturity date is the date on which the principal amount of a security becomes due and payable to the holder. It applies to fixed-income securities like bonds, notes, bills where the issuer must repay the principal on the maturity date.

At maturity, the debt is fully repaid. The security might cease to exist after maturity. Maturity dates affect interest rate risk - longer terms have higher risk. The final coupon payment is made on the maturity date.

What is a due date?

The due date is the date on which a debt payment is due to be paid by a borrower to a lender. It applies to loans, mortgages, credit cards, accounts receivables where periodic payments are required.

A due date recurrence can be monthly, quarterly, annually based on the terms. Missing a due date can result in late fees or interest charges.

Related functions

Excel Function	Description
DATEDIF(start_date, end_date, unit)	Returns the time between two dates in specified units like complete years or months
EDATE(start_date, months)	Returns the date that is the indicated number of months before or after start_date
EOMONTH(start_date, months)	Returns the last day of the month before or after start_date by months
MONTH(date)	Returns the month of a date (1-12)
DATE(year, month, day)	Returns an Excel date

EOMONTH function Syntax

EOMONTH(start_date, months)

EOMONTH function Arguments

start_date	Required. A date that represents the starting date. Don't use text dates, use Excel dates, see comments below.
months	Required. A number that determines how many months before or after the start date. A negative value returns a date earlier than the start_date.

EOMONTH function example

The image above shows the EOMONTH function cell D3 calculating the last day of the month based on a start date specified in cell B3 and the number of months specified in cell C3.

Formula in cell D3:

The function calculates 5/31/2030 based on the start date 1/1/2030 and add 4 months to that. The last day in May 2030 is 31.

Calculate quarterly dates for the last day of a given month

This example demonstrates how to calculate four different dates in the same calculation using arrays in Excel. The calculated dates are exactly three months a part from the start date and is the last date in that particular month.

Formula in cell D3:

{3;6;9;12} is an array of numbers separated by a semicolon. Excel performs four different calculations in the same cell and returns an array to cell D3 and the cells below as far as needed. This is called spilling and is a new feature in Excel 365.

Calculate bi monthly dates for the last day of a given month

This example demonstrates how to calculate six different dates in the same calculation using arrays in Excel. The calculated dates are exactly two months a part from the start date and is the last date in that particular month.

Formula in cell D3:

Explaining formula in cell D3

Step 1 - Create a sequence from 2 to 12 with step 2

The SEQUENCE function creates a list of sequential numbers.

Function syntax: SEQUENCE(rows, [columns], [start], [step])

SEQUENCE(6,,2,2)

returns

{2;4;6;8;10;12}

Step 2 - Calculate dates

EOMONTH(B3,SEQUENCE(6,,2,2))

becomes

EOMONTH(B3,{2;4;6;8;10;12})

and returns

{49399;49460;49521;49582;49643;49705}.

EOMONTH function tips

Use a negative number as the month argument to get a date before the start date. The image above shows the start date in cell B3, -2 in cell C3 which represents the month argument and the result in cell D3.

1/1/2035 minus two months is November 2034 and the last date in that month is 11/30/2034.

EOMONTH function not working

An invalid date demonstrated in cell B5 returns a #VALUE! error displayed in cell D5. Use the method explain here to convert invalid dates to dates that work: DATEVALUE function

The EOMONTH function truncates a decimal value representing the months argument.

What is truncate?

Removing the decimal leaving only the whole number. For example, truncate 7.9 and you get 7.

EOMONTH function alternative

Formula in cell D3:

Explaining formula in cell D3

Step 1 - Calculate the year

The YEAR function converts a date to a number representing the year in the date.

Function syntax: YEAR(serial_number)

YEAR(B3)

becomes

YEAR(49310)

and returns "2035".

Step 2 - Calculate the month

The MONTH function extracts the month as a number from an Excel date.

Function syntax: MONTH(serial_number)

MONTH(B3) +C3 + 1

becomes

MONTH(49310) + 4 + 1

becomes

1 + 4 + 1

and returns 6.

Step 3 - Calculate the Excel date

The DATE function returns a number that acts as a date in the Excel environment.

Function syntax: DATE(year, month, day)

DATE(YEAR(B3),MONTH(B3)+C3+1,1)

becomes

DATE(2035,6,1)

and returns "6/1/2035" (49460)

Step 4 - Subtract Excel date by 1

DATE(YEAR(B3),MONTH(B3)+C3+1,1) - 1

becomes

49460 - 1

and returns

49459 (5/31/2035)

'EOMONTH' function examples

Functions in 'Date and Time' category

The EOMONTH function function is one of 22 functions in the 'Date and Time' category.

Excel function categories

Excel categories

Comments (3)