24-hour clock

The 24- count ( or astronomical hours counting) is now overwhelming count of 24 equal length, equinoctial hours, in which the full - day ( the light of day and the night together ) is divided. Is on the so-called Great clock continuously from the first (1st ) counted up to the 24th hour. The time shown for the first ( 1 ) hour is from 0:00 bis 1:00 clock clock, for 24 hours from 23:01 clock to 24 clock. Is counted from midnight, but in the count changes the minute 23:59 clock directly to the minute 0:00 clock the following day, between two minutes there is none, only logical second.

History

The 24 -hour count was introduced in the late Middle Ages, when simultaneously the separate counting of the clear day and the night was abandoned with 12 unequal length, temporal hours with the advent of mechanical gear clocks. However, the old hour counts remained in some parts of Europe until the 18th century in use. The 24 -hour count is now the standardized hours counting the ISO ( ISO 8601 ). This system has prevailed in most countries of the world or has remained there in application.

For practical reasons, an artificial separation with the use of so-called small clock naturalized located approximately in the 16th century again. This clock makes in 24 hours two rotations and display at each point of the dial always two of the 24 hours of the full - day to 1 clock and 13 clock than 1 clock to 12 clock and 24 clock 12 clock. Double counting is called a 2-by- 12-hour count or short as 12-hour count. The reasons for this step, mention may be

• The first public mechanical clocks were striking, not indicating tower clocks. For the annoying miscounting stopped from 13 at least, were counted a second time from 1
• The Small mechanical clock could be easier and construct for longer life than the Great Clock.

12 versus 24 hours

The 12-hour count is now Australia, Canada (except Quebec ), New Zealand, the Philippines and the United States with am ( ante meridiem ) and pm (post meridiem ) used officially in yet. In many European countries it is still anchored in everyday language, including specific phrases for hours of parts, for example, " half four " for 15:30 clock, the reference to the " hour or part thereof ". With quarter of an hour are regional " Four quarters " and " quarter past (or over ) Three", and " quarter to four" or " three-quarter four".

The 24 -hour count has in the countries that prefer the 12-hour count, special designations:

• Military time in Canada and the United States,
• Army time in Australia,
• Railway time or radio time in various parts of the world.

With the advent of digital clocks, the 24 -hour counting prevails even in those countries that do not formally apply. In daily life loses the 12-hour count in importance. But analog clocks with 24 -hour display remain rare.

The introduction of the 24 - hour time indication in Germany took place in Bahn Long-Distance 15 May 1927.

Special

Long before the Middle Ages were 24 -hour counts in use, but mostly with sunrise began ( Babylonian or Greek hours ), isolated also from sunset ( Italic or Bohemian hours).

The astronomers used at certain epochs one hours counting from noon, so as not to have a different date during the nocturnal hours. A rest of it has been preserved in the Julian Date ( JD ), whose day count begins as 12:00 clock world time, however, rather than working hours with daily fractions.