Kyle,
It doesn't appear at this time (05/01/08), that the technology of the DTA Boxes will let you do Timed Off-hour recordings, except for the following.
You'd have to set the channel up on the Box, start and stop the Recorder, or,
leave the Box on, and on the right channel, and time your recorder to record that. Then change the Box channel to record something else. UKKK!
And before you buy one, keep in mind that.....
Some DTA Boxes don't even have Remote Controls, most don't have HD Tuners in them, and the coupons do NOT apply to ALL Boxes !
If you decide to get any Recorder, make sure it has an ATSC (Digital Tuner) in it (or both NTSC & ATSC), and just save the trouble of getting a Box.
So, the way it is now, these Boxes are basically for "watching" TV.
Hopefully as time passes, they'll get it together and give us something that works better for us.
Have a good Day !

PS: There's a very detailed discussion about DTV Boxes at.....
what-kind-converter-need-t5.html