What column type is required to use MONTH to return number of new lines in a certain month?

CatB

I've been trying to count lines by month, I have the column I want searched set to a date column type.

=COUNTIF([Date Opened]:[Date Opened], MONTH(1))

I'm getting a invalid data type error.

Melissa Yamada

Hello @CatB

It looked like your Date column has either an empty cell or a non-date value so you need to account it using an IFERROR function. Since having either an empty cell or a non-date value will throw an error and that causes the #INVALID DATA TYPE error message.

Try this:

=COUNTIF([Date Opened]:[Date Opened], IFERROR(MONTH(@cell ), 0) = 1)