page_title: 24-hour analog dial
hierarchical_section_title: 24-hour analog dial
caption_attribution_description: English: Pocket sundial from the 16th Century, from the Louvre in Paris
context_page_description: Clocks and watches with a 24-hour analog dial have an hour hand that makes one complete revolution, 360°, in a day. The more familiar 12-hour analog dial has an hour hand that makes two complete revolutions in a day.
  Twenty-four-hour analog clocks and watches are used today by pilots, scientists, and the military, and are sometimes preferred because of the unambiguous representation of a whole day at a time. Note that this definition refers to the use of a complete circular dial to represent a 24-hour day. Using the numbers from 0 to 23 to mark the day is the 24-hour clock system.
  Sundials use 24-hour analog dials—the shadow traces a path that repeats approximately once per day.
  Many sundials are marked with the double-XII or double-12 system, in which the numbers I to XII are used twice, once for the morning hours, and once for the afternoon and evening hours. So VI appears twice on many dials, once near sunrise and once near sunset.
  Modern 24-hour analog dials—other than sundials—are almost always marked with 24 numbers or hour marks around the edge, using the 24-hour clock system. These dials do not need to indicate AM or PM.
context_section_description: Clocks and watches with a 24-hour analog dial have an hour hand that makes one complete revolution, 360°, in a day (24 hours per revolution). The more familiar 12-hour analog dial has an hour hand that makes two complete revolutions in a day (12 hours per revolution).
  Twenty-four-hour analog clocks and watches are used today by pilots, scientists, and the military, and are sometimes preferred because of the unambiguous representation of a whole day at a time. Note that this definition refers to the use of a complete circular dial to represent a 24-hour day.  Using the numbers from 0 to 23 (or 1 to 24) to mark the day is the 24-hour clock system.
  Sundials use 24-hour analog dials—the shadow traces a path that repeats approximately once per day.
  Many sundials are marked with the double-XII or double-12 system, in which the numbers I to XII (or 1 to 12) are used twice, once for the morning hours, and once for the afternoon and evening hours. So VI (or 6) appears twice on many dials, once near sunrise and once near sunset.
  Modern 24-hour analog dials—other than sundials—are almost always marked with 24 numbers or hour marks around the edge, using the 24-hour clock system.  These dials do not need to indicate AM or PM.
caption: A sundial showing all 24 hours; impractical but symmetrical
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