BeginnerDate & Time
Find month-end due dates with EOMONTH
Set a due date to the last day of the following month, whatever its length.
EOMONTH
5 min15 points
EOMONTH
Returns the last day of the month a given number of months from a date.
Syntax
EOMONTH(start_date, months)
Date & Time.
Practise EOMONTH1 interactive exercise, free, no account needed
A worked example
=EOMONTH(B2,1)
Returns Oct 31, 2026 for an invoice dated Sep 14, 2026
Moves one month forward and lands on the last day of that month, whatever its length.
Where it goes wrong
Zero months is the end of the same month, one is the end of the next. Adding 30 days instead never lands on a month end by design and drifts by a day or two every month.
What the exercises catch
Each of these is a wrong turn the practice exercises recognise and name. They are the misconceptions, not the answers.
- Thirty days after 14 September is 14 October, which is not a month end at all. The terms say the last day of the following month, and months are not all thirty days long — you need a function that knows the calendar.Find month-end due dates with EOMONTH
- Zero months gives the end of the invoice's own month, 30 September. The terms are the month after, so the second argument needs to move one month forward.Find month-end due dates with EOMONTH
Practise EOMONTH
Knowing what a function does and being able to write it from memory are different skills. These close the gap.
All EOMONTH practice exercises →