A wristwatch has a 24-hour display if its hour hand completes one complete rotation around its own axis over the course of an entire day and its dial is calibrated from 1 to 24. This type of display is rarely seen because it takes time to get used to and is difficult to read. Some wristwatches also have two separate hour hands: one of them rotates around its own axis once every 12 hours; the other hour hand completes the same orbit in 24 hours.