I find this to be true as well. I have nerve damage/pressure from bad back. If I miss a dose before bed, I almost invariably get a calf cramp in the early morning hours before waking. Very annoying, only way to get rid of it is get out of bed and stand up on it. I think flooding the body with the magnesium before bed, before it has a chance to maybe get rid of excess perhaps, because taking it too far from bedtime I'll still have twitches and cramps.