EOMONTH

To calculate the last day of a certain month, you can use the built-in EOMONTH function, which stands for End of Month.
The function consists of two arguments: The date of whose month you would like to find the last day, and the amount of months from that date you would like to apply the function to.
For example, if we want to find the last day of the current month, we enter write equals, EOMONTH, select today’s date, and write zero. We see that February’s last day is the 29th.
To get the last day of the next month, March, we simply replace the 0 with a 1, and we see that it has 31 days.
We can also subtract months from the formula. If we replace the 1 with a -5, we get the last day of the ninth month, September, as 2 – 5 is -3, and 12 – 3 is 9.
This lesson has shown how to get the last day of any month.