Set at any 15 minute increment during a 24 hour period. They are very reliable and durable. A significant step towards lifestyle aromatherapy.

In case of power failure, re-set to the current time of day by simply turning the dial.
Manual timers are becoming a popular addition to high output diffusers. They are extremely easy to use and operate. If you don't like to sit down and program digital widgets, then this is the timer for you. It will easily pay for itself within the first few bottles oil simply by not wasting it.