Swatch Internet Time is a concept marketed by the Swatch corporation as an alternative measure of time. Instead of hours and minutes, the 24 hour day is divided up into 1000 parts called ".beats", each .beat being 1 minute and 26.4 seconds, and equal to the decimal minute introduced after the French Revolution. There are no time zones; instead, the new scale of Biel Mean Time (BMT) is used, based on the company's headquarters in Biel, Switzerland. Despite the name, BMT does not refer to mean solar time at the Biel meridian, but is equivalent to Central European Time, or UTC+1.

The most distinctive aspect of Swatch Internet Time is its notation; as an example, "@248" would indicate a time 248 .beats after midnight, equivalent to a fractional day of 0.248 CET, or 4:57:07.2 UTC. Although Swatch does not specify units smaller than one .beat, third-party implementations have extended the standard by adding "centibeats" or "sub-beats" as a decimal fraction, for extended precision: @248.000. No explicit format was provided for dates, although the Swatch Web site displays the Gregorian calendar date in the order day-month-year, separated by periods and prefixed by the letter d (d31.01.99).

Like UTC, Internet time is the same throughout the world. For example, when the time is 875 .beats, or @875, in New York, it is also @875 in Tokyo.

Its novelty and the usage of the decimal time system makes it more attractive and simpler to use for some people than the traditional Babylonian system of time reckoning (24 hours of 60 minutes of 60 seconds). For example, knowing that there are 1000 .beats in a day, if one learned some event took 5500 .beats to complete, it would be immediately known that it happened over five and a half days. On the other hand, if one learned that some event took place over 132 hours, it would result in no immediately clear idea of the duration covered without some form of calculation.

Although there are advantages to the system, it has some major drawbacks:

• The use of Central European Time (UTC+1) to denote 0 .beats introduces an unwanted additional meridian (at 15°E); the Greenwich Meridian (UTC) is the standard international meridian.
• The phrase "Biel Mean Time" is misleading, as there is no connection to any merdian that runs through Biel (which is at approximately 7°15'E).
• The second, and not the .beat, is the basic SI unit of time measurement. The use of an additional time system adds unnecessary complexity for scientific calculations.
• Some criticize that the Internet time system is more of a commercial marketing attempt rather than a real system.
• No submultiple units are specified, prompting divergent extensions by third parties. Officially the system is accurate to 1 minute and 26.4 seconds.
• The noon is at different .beat on every time zone. For example in Helsinki it is noon at @417; in New York City, however, it is noon at @708. This is confusing and nonintuitive. The sunrise and sunset are also very different.

Most Internet standards actually use either local civil time with a time zone indicator, or the global UTC time standard.

The proposal timescale was announced October 23, 1998, in a ceremony marked by the presence of Nicolas G. Hayek , President and CEO of the Swatch Group, G.N. Hayek, President of Swatch Ltd., and Nicholas Negroponte, founder and director of the MIT Media Lab.

During 1999, Swatch produced several models of watch that displayed Swatch Internet Time as well as standard time, and convinced a few Web sites to use the new format. It is also widely used as a time reference on ICQ. Outside these areas, though, it appears to be infrequently used.

See also

• Decimal time

External links

• Swatch Internet Time brochure
• The current Internet time
• A short description of Internet time
• Hex Clock