I have a form that shows from and through dates. The from date is a fixed date - "Patient admission date" through "the last day of the previous month" previous to the "current" date. My current DateSerial function is =DateSerial(2000,5,1-1). Can I automatically update the "month" and "year"?

I assume you wish to use the current Month and Year from the computer's current date. If this is true, try this:

=DateSerial(Year(Now()),Month(Now()),1-1)

HTH
RDH

Thanks very much. The online help showed DateSerial Function would only work with "numeric" input (year "2000", Month "5") and so on. It works perfectly.