Many modern air conditioners have various functions, such as a regular mode for making indoor temperature and humidity more comfortable, and a sleep mode for bedtime.
Sleep mode is a function for conditioning indoor air so that a user can sleep comfortably. One particular example of an air conditioner having the sleep mode is an air conditioner for adjusting indoor temperature in accordance with a user's biological rhythms during sleep, such as the air conditioner disclosed in Japanese Laid-open Patent Document No. 5-106899, for example.