The Arm Night mode is perfect for when you are home and asleep. Xfinity Home security features are activated just like the Away mode, but motion sensors do not get activated unless customized to be.
By default motion sensors that are inactive in the Arm, Night mode is in the area where there may be activity at night time. A motion sensor active in the Arm Night mode will immediately trigger an alarm if crossed, which is why these must be installed in areas such as the attic, garage, or basement.