Good afternoon --

I'd like to limit entries in a column to dates in the current month. I'm
using the Data Validation Dates Between approach. My first date works
fine:

=DATE(YEAR(TODAY()),MONTH(TODAY()),1)

My ending date formula works fine in the spreadsheet but, when I copy it
into the data validation box, it gives me an error message. Here's the
formula:

=EOMONTH(TODAY(),0)

The error message says I can't make reference to other worksheets or
workbooks.

Can someone point me in the right direction (as befuddled as I may be)?

Thanks in advance.