time //ubuntu

ubuntu

sys time (timezone)<>bios time (UTC)

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Usage: hwclock [function] [options...]
Functions:
--show        read hardware clock and print result
--set         set the rtc to the time given with --date
--hctosys     set the system time from the hardware clock
--systohc     set the hardware clock to the current system time
--adjust      adjust the rtc to account for systematic drift since the clock was last set or adjusted
Options:
--utc         the hardware clock is kept in coordinated universal time
--localtime   the hardware clock is kept in local time
--date        specifies the time to which to set the hardware clock

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time zone
sudo dpkg-reconfigure tzdata

check
date; hwclock --show

set2bios
sudo hwclock --localtime --hctosys
sudo hwclock --systohc

set2hw
hwclock --set

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sudo vi /etc/default/rcS
UTC=yes >>> UTC=no

sudo ntpdate time.stdtime.gov.tw
sudo hwclock -w

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#get timezone
sudo tzselect 
     
#change 
sudo ln -sf /usr/share/zoneinfo/Asia/Taipei /etc/localtime 
     
#syn 
sudo ntpdate pool.ntp.org 
     
#update BIOS 
sudo hwclock -w 
     
#scheduled 
sudo crontab -e