Introduction to the method of modifying time zone under Linux

Source: Internet
Author: User
Tags current time

has been used to set the date, this reference online data, and finally the whole.

The Linux clock is divided into system clocks (systems Clock) and hardware (real time Clock, short RTC) clocks. The system clock is the clock in the current Linux kernel, and the hardware clock is the battery-powered clock on the motherboard, which can be set in the BIOS. When Linux is started, the hardware clock will read the system clock settings, and the system clock will be independent of the hardware operation.

All the commands (including functions) in Linux are set by the system clock. In Linux, the commands for clock viewing and setting are mainly date, hwclock, and clock. The clock and hwclock usages are similar, except that the clock command supports the Alpha hardware system in addition to the x86 hardware system.

1. Date

View system time

# date

Set system time

# date--set "07/07/06 10:19" (Month/day/year: minutes: SEC)

2, Hwclock/clock

View hardware Time

# Hwclock--show

# clock--show

Set Hardware time

# Hwclock--set--date= "07/07/06 10:19" (Month/day/year: minutes: SEC)

# clock--set--date= "07/07/06 10:19" (Month/day/year: minutes: SEC)

3, hardware time and system time synchronization

According to the previous version, reboot the system, the hardware time will read the system time, to achieve synchronization, but without restarting, you need to use the Hwclock or clock command to achieve synchronization.

The hardware clock synchronizes with the system clock:

# Hwclock--hctosys (HC represents hardware time, SYS represents system time)


# clock--hctosys

system clock and Hardware clock sync:

# Hwclock--SYSTOHC


# clock--SYSTOHC

4, Time zone settings

# Tzselect

Please identify a location so this time zone rules can be set correctly.

Please select a continent or ocean.

1) Africa

2) Americas

3) Antarctica

4) Arctic Ocean

5) Asia

6) Atlantic Ocean

7) Australia

8) Europe

9) Indian Ocean

) Pacific Ocean

One) None-i want to specify the time zone using the Posix TZ format.

#? Input 5, Asia

Please select a country.

1) Afghanistan Israel) Palestine

2) Armenia) Philippines

3) Azerbaijan Jordan) Qatar

4) Bahrain Kazakhstan) Russia

5) Bangladesh Korea) Saudi Arabia

6) Korea (South) Bhutan) Singapore

7) Brunei Kuwait) Sri Lanka

8) Cambodia Kyrgyzstan) Syria

9) Laos Taiwan

Cyprus) Lebanon Tajikistan

Timor Macau) Thailand

Georgia) Malaysia Turkmenistan

(Kong) Mongolia) United Arab Emirates

India) Myanmar (Burma) Uzbekistan

Indonesia) Vietnam Nepal)

 Yemen Oman)

Iraq) Pakistan

#? Input 9, China

Please select one of the following time zone regions.

1 East China-beijing, Guangdong, Shanghai, etc.

2) Heilongjiang

3) China-gansu, Guizhou, Sichuan, Yunnan, etc.

4) Tibet & most of Xinjiang Uyghur

5) southwest Xinjiang Uyghur

#? Input 1, the

The following information has been given:


East China-beijing, Guangdong, Shanghai, etc.

Therefore tz= ' Asia/shanghai ' would be used.

Local Now:fri June 7 10:32:18 CST 2006.

Universal is Now:fri June 7 02:32:18 UTC 2006.

is the above information OK?

1) Yes

2) No

#? Enter 1 to confirm

If you do not use the Tzselect command, you can modify the file change time zone.

# Vi/etc/sysconfig/clock

Zone=asia/shanghai (check the/usr/share/zoneinfo file below)



# Rm/etc/localtime

# Ln-sf/usr/share/zoneinfo/asia/shanghai/etc/localtime

Reboot can be done.

How Linux modifies system time and time zone method supplements:

To modify a time zone:


Find the appropriate time zone file/usr/share/zoneinfo/asia/shanghai

Replace the current/etc/localtime file with this file.

Or find the server you think is Standard time, and then



Modify the/etc/sysconfig/clock file and modify it to:

Zone= "Asia/shanghai"



Modified Date Time:


Modify Date Time with date

#date-S 08/24/2006

#date-S 13:02:00


Synchronizing the BIOS clock, forcing the system time to be written to the CMOS


Also, view Bois time with #hwclock-R

#tzselect can modify the time zone interactively

Linux Modify system time zone

1. View the current time zone

# Vi/etc/sysconfig/clock

2. Modify Settings Time zone

Method (1) # Tzselect Method (2 is limited to Redhat Linux and CentOS) # Timeconfig

3. Copy the appropriate time zone file, replace the system default time zone

# cp/usr/share/zoneinfo/$ main time zone/$ time zone/etc/localtime for Chinese server: # cp/usr/share/zoneinfo/asia/shanghai/etc/localtime

4. Write the current time to the BIOS for permanent entry (avoid failure after reboot)

# Hwclock

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