Don't worry...the reporting time is a 24 hour period that starts at noon GMT. So even if you did 2 hours in one session and 4 hours later did another 2 hours and 3 hours later you did another 2 hours....it all totals to 6 hours during that 24 hour period. So it all counts towards compliance.
Shift workers...it all works out in the end using the 24 thing. If you can't use it for a couple of nights....as long as you have more than 4 hours logged of usage for 70% of 30 consecutive nights you will be good to go. If you get in a pinch and compliance is iffy....use the machine while awake and watching TV for a few hours. The machine won't know you aren't asleep and neither will anyone else but it still counts as "usage".



