The Yamaha Pocketrak 2G and CX have a similar feature. In the Pocketrak units, you can program the recording start time up to 24 hours in advance, and the recording duration. The duration choices are 30 minutes, 1 hour, 2 hours and until the memory is full. Once set, you can turn off the recorder. At the appointed hour, the recorder wakes up and starts recording.
The Sound Devices 722 has a feature like this, but I think you have to leave the recorder powered up in record/pause mode for it to work.
This feature is useful if you need to record a TV or radio broadcast at a particular time. It's also useful for nature recording. Setting the recorder to start by itself at 4am is a great way to catch the dawn chorus while you remain in dreamland.
Flintstone