A real-time clock module includes a switch circuit that is electrically coupled to a first node to which a first power supply voltage is applied and a second node to which a second power supply voltage is applied and switches between outputting the first power supply voltage and outputting the second power supply voltage, a power supply detection circuit that detects a voltage value of the first power supply voltage, a switch control circuit that controls the switching of the switch circuit based on an output of the power supply detection circuit, a constant voltage circuit that outputs a constant voltage signal based on the output of the switch circuit, and a current control circuit that controls a current supplied to the constant voltage circuit, in which, when where the switch control circuit switches the switch circuit, the current control circuit increases the current supplied to the constant voltage circuit.