http://www.itshanghai.net/technology/wdzl_windowsxp/UTC (Universal time coordinated) is a universal coordination, the two are almost the same, both refer to the GMT, but the UTC address is more formal. Today, when doing some DC testing, there is a time problem, because there is an English version of the computer XP (the time zone default is the West VIII zone), the time of the login failed to log in. After logging on to this machine, when you look at the time zone, there are some puzzles about the time zone and GMT, check the data, look at the map, and finally get the problem figured out. In this process, GMT and time zone have some new understanding, write to share with you. DC-related knowledge is not involved here, only GMT and time zone are discussed.
GMT, full name Greenwich Mean time, that is Greenwich Standard, why is there such a moment? The reason is not much to say, online a lot, in fact, its appearance is to standardize the global time, countries have a fixed time for the reference point to calculate the local time. The International Meridian Conference was held in Washington, D.C., in 1884 to determine that Greenwich is a 0-degree place. People divide the Earth into 24 equal parts, each part is a time zone, each time zone across the longitude 15 degrees, the time is exactly 1 hours, to greenway the time zone for the location of the central time zone, we now assume that GMT is the morning of January 10 (that is, 0 o'clock), the West one time zone, minus one hour, Then the local time is January 9 night 23 o'clock the whole, to the east a time zone, then add an hour, then the local time is January 10 1 o'clock in the morning, and so on, and so on, China at 120 degrees east longitude, can calculate, (east longitude 120°-longitude 0°) The degree is divided by 15, that is 8, so China in the Eastern eight district, then, At this time China is January 10 8 o'clock in the morning the whole.
There is a calculation formula, local time =UTC + time zone difference. Maybe a lot of friends would ask, what is UTC? What's the difference from GMT? UTC (Universal time coordinated) is a universal coordination, the two are almost the same, both refer to the GMT, but the UTC address is more formal. For the formula, let's make a few examples to understand.
First need to explain that the time zone difference is positive or negative, in the time zone, the west is negative, toward the east is positive, what does it mean? For example, China's time zone is the East eight district, that is, the +08:00, the complete wording is gmt+08:00, the Eastern time zone is the West five, that is, -05:00, the complete writing is gmt-05:00, because this difference needs to participate in the operation, so can not omit the preceding symbol.
For example, it is Beijing time February 5, 2009 13:40, I would like to know the time of New York (located in West Five), how to calculate it? Let's look at the formula: local time =UTC + time zone difference, according to the company first need to get the current UTC time is how much. UTC in the time zone, which is 0,13:40=utc+08:00, gets UTC February 5, 2009 05:40, and then uses this formula, by New York time =05;40+ ( -05:00), to arrive at New York time =0;40 because the count is positive, which means that the date has not changed, or February 5 , so that we can calculate that the time of the United States is February 5, 2009 0 o'clock in the morning 40.
These are the morning by a domain time difference problem extended out about GMT and timezone understanding, hope to help everyone
In-depth understanding of GMT and time zones within Windows systems
