改變linux系統的時間
阿新 • • 發佈：2018-11-11
一、背景：設定系統的時候選擇市區明明是中國上海，但是後來用date命令檢視時間時，時間又不對了。
相關詞語解釋
系統時間（System Clock）：是指當前Linux Kernel中的時鐘。
硬體時間（Real Time Clock，簡稱RTC）：主機板上由電池供電的時鐘，這個硬體時鐘可以在BIOS中進行設定。
當Linux啟動時，硬體時鐘會去讀取系統時鐘的設定，然後系統時鐘就會獨立於硬體運作。Linux中的所有命令（包括函式）都是採用的系統時鐘設定。
出現上述問題的原因是有時候硬體時間和系統時間不同步。
解決方法：
[[email protected] ~]# tzselect Please identify a location so that 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 10) Pacific Ocean 11) none - I want to specify the time zone using the Posix TZ format. #? 5 Please select a country. 1) Afghanistan 18) Israel 35) Palestine 2) Armenia 19) Japan 36) Philippines 3) Azerbaijan 20) Jordan 37) Qatar 4) Bahrain 21) Kazakhstan 38) Russia 5) Bangladesh 22) Korea (North) 39) Saudi Arabia 6) Bhutan 23) Korea (South) 40) Singapore 7) Brunei 24) Kuwait 41) Sri Lanka 8) Cambodia 25) Kyrgyzstan 42) Syria 9) China 26) Laos 43) Taiwan 10) Cyprus 27) Lebanon 44) Tajikistan 11) East Timor 28) Macau 45) Thailand 12) Georgia 29) Malaysia 46) Turkmenistan 13) Hong Kong 30) Mongolia 47) United Arab Emirates 14) India 31) Myanmar (Burma) 48) Uzbekistan 15) Indonesia 32) Nepal 49) Vietnam 16) Iran 33) Oman 50) Yemen 17) Iraq 34) Pakistan #? 9 Please select one of the following time zone regions. 1) Beijing Time 2) Xinjiang Time #? 1 The following information has been given: China Beijing Time Therefore TZ='Asia/Shanghai' will be used. Local time is now: Tue Oct 9 09:21:45 CST 2018. Universal Time is now: Tue Oct 9 01:21:45 UTC 2018. Is the above information OK? 1) Yes 2) No #? 1 You can make this change permanent for yourself by appending the line TZ='Asia/Shanghai'; export TZ to the file '.profile' in your home directory; then log out and log in again. Here is that TZ value again, this time on standard output so that you can use the /usr/bin/tzselect command in shell scripts: Asia/Shanghai [[email protected] ~]# TZ='Asia/Shanghai'; export TZ [[email protected] ~]# TZ='Asia/Shanghai'; export TZ [[email protected] ~]# vim .p .pki/ .pulse/ .pulse-cookie [[email protected] ~]# vim .p .pki/ .pulse/ .pulse-cookie [[email protected] ~]# vim .profile