The buttons there on the keypad "CHIME".
Press it and whatever zone lit is the zone currently in chime,
Press the corresponding number of the zone that's lit to turn the zone in chime off.
Press reset.
The chime has nothing to do with day mode, but simply means the system is in a standby unarmed state (not set).
Maybe you should read through the user manual and get to know your alarm. :)
e manno, June 2013