Restrict specific week days and times.

net user simon /time:M-F,17:30-22:30;Sa-Su,16:30-22:30

Remove restrictions

net user simon /time:all

windows

// mount windows root then,

cd /mnt/Microsoft/Windows/System32/config/
cp SAM SAM.original
chntpw -l SAM
chntpw -i SAM