An air conditioning system comprising: an air conditioner that includes an outdoor unit including an outside air temperature sensor to detect an outside air temperature and an indoor unit including an indoor unit control section to control air conditioning operation, the indoor unit being communicable with the outdoor unit; and a remote controller communicable with the indoor unit, wherein the remote controller includes: a schedule storage section to store information on an operation schedule of the air conditioner for each date and time set in advance, a reference temperature for determining an operation mode of the air conditioner, and an outside air temperature correction value for correcting the outside air temperature; the air conditioning system characterised in that: the remote controller includes an operation mode determination section configured to select the operation mode from among cooling, blowing, and heating using the information on the operation schedule, a corrected outside air temperature obtained through correction of the outside air temperature with the outside air temperature correction value, and the reference temperature, and the indoor unit control section controls the air conditioning operation using the reference temperature as a target temperature in the operation mode determined by the operation mode determination section. an air conditioner that includes an outdoor unit including an outside air temperature sensor to detect an outside air temperature and an indoor unit including an indoor unit control section to control air conditioning operation, the indoor unit being communicable with the outdoor unit; and a remote controller communicable with the indoor unit, wherein the remote controller includes: a schedule storage section to store information on an operation schedule of the air conditioner for each date and time set in advance, a reference temperature for determining an operation mode of the air conditioner, and an outside air temperature correction value for correcting the outside air temperature; the air conditioning system characterised in that: the remote controller includes an operation mode determination section configured to select the operation mode from among cooling, blowing, and heating using the information on the operation schedule, a corrected outside air temperature obtained through correction of the outside air temperature with the outside air temperature correction value, and the reference temperature, and a schedule storage section to store information on an operation schedule of the air conditioner for each date and time set in advance, a reference temperature for determining an operation mode of the air conditioner, and an outside air temperature correction value for correcting the outside air temperature; the air conditioning system characterised in that: the remote controller includes an operation mode determination section configured to select the operation mode from among cooling, blowing, and heating using the information on the operation schedule, a corrected outside air temperature obtained through correction of the outside air temperature with the outside air temperature correction value, and the reference temperature, and the indoor unit control section controls the air conditioning operation using the reference temperature as a target temperature in the operation mode determined by the operation mode determination section.