I subscribe to the IRS newsletters and alerts so I get spammed with ever changing tax information on a daily basis, and I belong to various online tax preparer groups and so I DID know about the deadline...the majority of my RMD clients take their distribution in December each year, so this really didn't apply to them.

As far as finding a list of all clients that are in the RMD age range, you could customize Homebase to include a date of birth, then organize that column by oldest first and it would throw all your RMD clients to the top of the list...clunky, but if your database is small, it could be helpful....being its the last day, Im not sure how much luck many of them would have getting it rolled back in on time though.