First Chapter - About Time

• About hwclock (Hardware clock/BIOS clock)

  • Write date to hwclock

    • hwclock -w = hwclock --systohc

  • Save hwclock to date

    • hwclock -s = hwclock --hctosys

  • Set hwclock

    • hwclock --set --date="8/11/2013 23:10:45"

  • Debug mode

    • hwclocl --debug

• About date (Linux kernel clock)

  • Convert day to seconds

    • $(date -d "2015-05-01" +%s)

  • Format (year-month-day hour:minute)

    • $(date +"%Y-%m-%d %H:%M")

  • Get UTC time

    • $(date -u)