Date Range and Null Values

Post Author: mrae

CA Forum: Formula

I want to pull up data that have been completed for the month, but also want to include null values. I did the following but didn't work.

(isnull({wrhwr.date_completed}) or {wrhwr.date_completed} => 4/1/2008 12:00:00AM or =<4/30/2008 11:59:59PM

Help, please?