Most spas are equipped with some such automatic controls. Spa control packages also include electronic thermostats and other sophisticated controls. The advantages of electronic controls are precision and low voltage. Most have digital readouts so you can precisely set the time and temperature desired, as well as programming a host of other features. Lastly, most electronic devices have small backup batteries so that when main power is interrupted, they don't lose the time of day or previous programming.
Repairs Lubricating a time clock is the only service and maintenance that a clock needs.
Otherwise they are cheap enough and can be replaced rather than fixing them. If a time clock fails, simply replace it. When replacing a unit, make sure it has the same voltage as the original clock. If it is housed in a waterproof box, buy the same brand to ensure a correct fit. Before starting the replacement, always remember to shut off the electricity at the breaker.