A time switch (1) includes a contact mechanism (40) switched to an activation state, in which the contact mechanism (40) electrically connects a power supply (2) and an electric device (3), or a deactivation state, in which the contact mechanism (40) electrically disconnects the power supply (2) and the electric device (3). The time switch (1) further includes a cam mechanism (30) that mechanically drives the contact mechanism (40) to switch the contact mechanism (40) between the activation state and the deactivation state, a rotation shaft (21) capable of transmitting torque to the cam mechanism (30), and a knob (22) that is coupled to the rotation shaft (21) to switch an operation state of the contact mechanism (40). In addition, the time switch (1) includes a ratchet mechanism (25) that allows rotation of the rotation shaft (21) when the knob (22) receives force that rotates the knob (22) in a first direction and restricts rotation of the rotation shaft (21) when the knob (22) receives force that rotates the knob (22) in a second direction.