Finally got them on p. 154:-
So that's 12 hours, or 6 hours if asleep or meditating, or 4 hours if they achieve a critical success in Meditation, to regain all of their Magic Points up to their available POW.Regaining Magic Points
Adventurers automatically regain Magic Points equal to their POW, less any POW dedicated to a Pact, every 12 hours. They will regain this amount in six hours if they are fully resting, such as sleeping, or through the use of the Meditation Advanced skill (see page 62).
Do they regain the Magic Points all at once, or do the Magic Points come back, a point at a time, over that period? What of someone who only spent part of those Magic Points?
Let's look at someone with a POW of 16. They're both going to be recovering Magic Points through sleep, so 6 hours.
One day, she spends all 16 Magic Points available to her, somehow survives the Resilience roll, and makes it to a safe spot to sleep it off. She would recover those Magic Points at a rate of 1 Magic Point per 22 minutes 30 seconds whilst sleeping. Let's say she only gets 180 minutes' sleep - 3 hours. Does that mean she only gets 8 Magic Points back and she has to wait another six hours to get the rest back, assuming she uses no more Magic Points?
And a second example. Someone else with 16 POW who spends, say, 4 Magic Points also opts to sleep it off. He has 12 Magic Points left. He's planning on spending 6 hours asleep, but he too only gets a little sleep - in this case, about 115 minutes, just shy of two hours. With POW 16 he'd have recovered 4 Magic Points by some 90 minutes, so when he wakes up would he be at full Magic Points?