With the increasing development of transportation, all countries are closed and their time standards can no longer meet world-wide requirements. Therefore, in 1880, a legal form of the United Kingdom established the Greenwich Standard Room (GMT). Since then, all countries in the world have agreed. Divide the world from east to west into 24 time zones.
Watch timer
The general table, continuously indicates the passage of time. The chronograph is different Chronograph is a professional name, of which chrono means "time" in Old English and Latin, and graph in English means "recording tool.", It is free to record the length of any period of time. Standard chronograph has 30 minutes or 12 hours of timing. Central seconds hand, usually stopped at the zero position. In order to show the timepieces are walking, most of them are equipped with a small moving second hand. Chronograph divided into two kinds, the first one is only an ordinary chronograph measurement object, and the other is a two-second hand measuring objects segmented chronograph.
Watch calendar
The "calendar" is an exaggeration of Chinese people, but the British more exaggerated, called "permanent calendar" form (Perpetual calendar). In fact, the so-called "permanent" only means that there is no need for manpower adjustment. If it is put on a daily basis, it does not need adjustment to indicate the correct date. That once every four hundred years, a leap year in February only 28, most of the calendar table can only accurately indicate that by 2100, IWC launched in 1985, "Da Vinci" can automatically be directed to 2500. The calendar is a complex mechanical watch that can indicate the date, month, week, and even can indicate the year and automatically adjust leap year.
Wrist watch average time difference
The so-called "time difference" refers to the difference between the average solar time and the stellar time based on real celestial bodies. The average solar time is commonly used time indicating the time, also known as the average time. In fact, the length of the day is not equal. The elderly have 24 hours 14 minutes, the short only 23 hours 44 minutes. People take the average 24 hours a day, for the convenience of everyday life. Stellar time does not measure the sun as the standard to another fixed star prevail, a day and night time is 23 hours 56 minutes and 41 seconds. This method is more accurate, suitable for astronomy and space science, but for the daily life will be out of touch, a lot of inconvenience.
The average time and star time are exactly four times a year, with differences for the rest of the year. Breguet studied outdated indications in the eighteenth century, adding dials on pocket watches and counter clocks that indicate the difference between the average sun and the stars.
In addition there is a time difference, known as the regional time difference. With the increasing development of transportation, all countries are closed and their time standards can no longer meet world-wide requirements. Therefore, in 1880, a legal form of the United Kingdom established the Greenwich Standard Room (GMT). Since then, all countries in the world have agreed. Divide the world from east to west into 24 time zones. To zero at the Greenwich Observatory near London, call meridian through the zero line, which divides the Earth into two hemispheres. The whole world is divided into 24 time zones from east to west with a longitude of 15 degrees in each zone and an hour difference with neighboring areas. This is the regional time difference.