# EOMONTH function: Description, Usage, Syntax, Examples and Explanation

## What is EOMONTH function in Excel?

EOMONTH function is one of Date and Time functions in Microsoft Excel that returns the serial number for the last day of the month that is the indicated number of months before or after start_date. Use EOMONTH to calculate maturity dates or due dates that fall on the last day of the month.

## Syntax of EOMONTH function

EOMONTH(start_date, months)

The EOMONTH function syntax has the following arguments:

**Start_date:**A date that represents the starting date. Dates should be entered by using the DATE function, or as results of other formulas or functions. For example, use DATE(2008,5,23) for the 23rd day of May, 2008. Problems can occur if dates are entered as text.**Months:**The number of months before or after start_date. A positive value for months yields a future date; a negative value yields a past date.Note: If months is not an integer, it is truncated.

## EOMONTH formula explation

- Microsoft Excel stores dates as sequential serial numbers so they can be used in calculations. By default, January 1, 1900 is serial number 1, and January 1, 2008 is serial number 39448 because it is 39,448 days after January 1, 1900.
- If start_date is not a valid date, EOMONTH returns the #NUM! error value.
- If start_date plus months yields an invalid date, EOMONTH returns the #NUM! error value.

## Example of EOMONTH function

Steps to follow:

1. Open a new Excel worksheet.

2. Copy data in the following table below and paste it in cell A1

Note: For formulas to show results, select them, press F2 key on your keyboard and then press Enter.

You can adjust the column widths to see all the data, if need be.

Date |
||

1-Jan-11 | ||

Formula |
Description |
Result |

=EOMONTH(A2,1) | Date of the last day of the month, one month after the date in A2. | 2/28/2011 |

=EOMONTH(A2,-3) | Date of the last day of the month, three months before the date in A2. | 10/31/2010 |