GMT
GMT is the abbreviation of Greenwich mean time, which can be translated into “Greenwich mean time” or “Greenwich mean time” in Chinese, or “Greenwich mean time” or “Greenwich mean time” in literal translation. Greenwich here is located on the Thames River southeast of London, UK. There is also a Greenwich town in the United States, but it has nothing to do with time
UTC
UTC is the abbreviation of coordinated universal time, which is translated into “world standard time” in Chinese. In literal translation, it can be translated into “coordinated universal time” or “coordinated world time”. At present, it means GMT time. Why does it mean GMT?This is because the prime meridian (the meridian is the longitude, the prime meridian is the 0 degree longitude) actually passes through Mecca in the west of Saudi Arabia, not Greenwich in the UK. At that time, the Royal Society of England temporarily determined Greenwich as the crossing point of the original meridian. In addition, Britain was in the period of prosperity, so the whole world used it to the present. Maybe it’s not impossible to change the day to Mecca time as the standard time. So we usually use UTC instead of GMT
PDT
PDT is the abbreviation of Pacific Daylight Time, translated into Chinese as “Pacific Daylight Time”, 7 hours later than UTC. Google once mentioned in its Adsense that “on 09-6-13, our engineers will maintain the website from about 10:00 a.m. to 2:00 p.m. on PDT.”
In fact, in addition to PDT time, there is a lot of time in North America:
summer in the United States begins on the first Sunday in April and ends on the last Sunday in October. Daylight saving time is one hour earlier than the normal time , and the corresponding PDT time is PST, pacific standard time. PST after daylight saving time
NST – Newfoundland standard time Newfoundland standard time
NDT – Newfoundland daylight time Newfoundland daylight time
ast – Atlantic Standard Time
ADT – Atlantic daylight time
EST – Eastern Standard Time
EDT – Eastern daylight time
CST – Central Standard Time
CDT – Central daylight time
MST – Mountain Standard Time
MDT – Mountain daylight time
PST – Pacific Standard Time
PDT – Pacific Daylight Time
Akst – Alaska standard time
akdt – Alaska daylight time
had – Hawaii Aleutian standard time Hawaii Aleutian standard time
hadt – Hawaii Aleutian daylight time Hawaii Aleutian daylight time
PST
PST is the Pacific Standard Time (Western eight districts), and the difference between PST and Beijing time (Eastern eight districts) is – 16 hours, that is, Beijing time minus 16 is PST time. PDT is one hour earlier than PST, which means the difference between PDT and Beijing time is – 15 hours 0
CST
CST (central standard time); It is Chinese standard time
GMT + 8 = UTC + 8 = CST
daylight saving time
Daylight saving time or daylight time
The United States and Canada originally implemented winter time at 2 a.m. on the last Sunday of October every year; Summer time will resume at 2 a.m. on the first Sunday of April Command timeconfig of changing time zone in Linux system Or 2010 U.S. daylight time: U.S. 2010 daylight time will start at 02:00 a.m. local time on March 14 At that time, the time server will automatically jump from 01:59:59 to 03:00:00 Beijing time Solve the problem of the wrong time Synchronize with the Greenwich mean time server and write as follows: [root@localhost~]#cp/usr/share/zoneinfo/America/Los_Angeles/etc/localtime
2010[root@localhost~]#cp/usr/share/zoneinfo/Asia/Shanghai/etc/localtime
hardware[ root@ftptest2 ~]#Ntpdate time-a.nist.gov
22 may 13:53:29 ntpdate [27810]: step time server 129.6.15.28 offset – 0.806279 sec
view time:
time[ root@ftptest2 ~]#Date
Tuesday, may 22, 2012 13:53:41 CST