Time delay relays and solid state timers use solid state electronic devices to provide a time delay. They may have displays, pots or other means of operator interface and electromechanical or solid state outputs. The number of time ranges on relays and timers are single or multiple. Single time ranges may be fixed or programmable. Timers with multiple time ranges can be programmed for multiple ranges. A minimum and maximum time setting must also be specified. Some relays and timers have field selectable time ranges. Time delay relays and solid state timers can have many timer functions or modes of operation, including ON-delay, OFF-delay, one shot and interval.