It then lets the user choose one power scheme that will be used during the working day and a second power scheme that will be used at night. During the day none of us want our PC to switch off the monitor or the hard drives or even power down just because we went for a coffee however, if we leave our PC on all night then after work hours it should be okay to power some of these devices down. When PowerSlave sees that the time has gone past the end of your working day it switches to the night-time power scheme. When you come back in the morning it will see that we are back in work hours and automatically switch back to your chosen day time plan