Minecraft wiki entry for daylock, associated text: On success, sets the game option "Always Day" to the argument value. If the argument is false, turns on the "Do Daylight Cycle" game option. If the argument is true or is omitted, turns off the "Do Daylight Cycle" game option and sets the time of day (time daytime value) to 5000 ticks, which is one in-game hour before noon.