Hmmm... I don't currently have any PTZs to experiment with myself, and I haven't considered taking a 'snapshot' at a particular time in a repetitive fashion.
You *could* likely schedule a separate archive to capture a minimum amount of video for the period in question, daily. The other task would then be to ensure the PTZ preset(s) fired before and after the period needed.
If I think of something, or get a chance to poke around today in the lab, I'll let you know if I come up with something.
Cheers!
Scott Olsen
Solutions Specialist
Bulletproof Solutions Inc.
Web: www.bulletproofsi.com