Functions: 1.time (12/24hr switch) and calendar display 2.alarm and snooze 3.indoor temperature and humidity 4.RF 433MHz outdoor temperature and humidity, up to 3 outdoor transmitters' receivable 5.temperature units: ℃/℉ 6.weather forecast display 7.low voltage indication for indoor unit 8.temperature trend of indoor/outdoor temperature 9.MAX/MIN records of temperature and humidity, auto-clear at 0:00