Can I use both the Timer ON and Timer OFF functions at the same time?

Yes, both timers can be set simultaneously for combined operation. For example, you can press TIMER OFF to set a stop time, then press TIMER ON to set a start time, and after 3 seconds both the 'TIMER ON' and 'TIMER OFF' indicators will remain on confirming both are activated. This is useful for scheduling the unit to stop after you go to bed and start again in the morning. (Page 7)