This just worked for me, made it last night got 6h 37m of sleep and 32 minutes awake so it moved £7 which I think was calculated from total sleep? Now I want to sleep earlier so that I don’t keep moving money out 
Also when I get enough sleep I’ve set it up for me to get £2 as a reward
It could also be that if I don’t get enough sleep that I should transfer out X amount for a coffee but I don’t drink coffee so this is one way to make me sleep earlier 
Hopefully in the future we would be able to add custom notes to pots via IFTTT?