A timer / calendar timer is a device that turns on or off industrial equipment, control panels, etc. or performs specific operations at a preset time. It is used for applications such as operation control of equipment and management of workpieces in industrial lines, etc. There are two types of timers: analog timers with excellent visibility by dial operation and digital timers with precise time control by key operation. The calendar timer is a timer that mainly sets the day and time with one week as one cycle. In addition to the same day of the week and the same time, on-off control of daytime at midnight and different times of the day is also possible. In addition, there are products such as solar time switches that perform on / off control using the annual sunset and sunrise times stored in the internal memory, solid-state timers that can control multiple time ranges with one unit, etc.