adjtime_config

ADJTIME_CONFIG(5)                File formats                ADJTIME_CONFIG(5)

NAME
       adjtime_config - information about hardware clock setting and drift
       factor

SYNOPSIS
       /etc/adjtime

DESCRIPTION
       The file /etc/adjtime contains descriptive information about the
       hardware mode clock setting and clock drift factor. The file is read
       and write by hwclock(8); and read by programs like rtcwake to get RTC
       time mode.

       The file is usually located in /etc, but tools like hwclock(8) or
       rtcwake(8) can use alternative location by command line options if
       write access to /etc is unwanted. The default clock mode is "UTC" if
       the file is missing.

       The Hardware Clock is usually not very accurate. However, much of its
       inaccuracy is completely predictable - it gains or loses the same
       amount of time every day. This is called systematic drift. The util
       hwclock(8) keeps the file /etc/adjtime, that keeps some historical
       information. For more details see "The Adjust Function" and "The
       Adjtime File" sections from hwclock(8) man page.

       The format of the adjtime file is, in ASCII.

   First line
       Three numbers, separated by blanks:

       drift factor
           the systematic drift rate in seconds per day (floating point
           decimal)

       last adjust time
           the resulting number of seconds since 1969 UTC of most recent
           adjustment or calibration (decimal integer)

       adjustment status
           zero (for compatibility with clock(8)) as a floating point decimal

   Second line
       last calibration time
           The resulting number of seconds since 1969 UTC of most recent
           calibration. Zero if there has been no calibration yet or it is
           known that any previous calibration is moot (for example, because
           the Hardware Clock has been found, since that calibration, not to
           contain a valid time). This is a decimal integer.

   Third line
       clock mode
           Supported values are UTC or LOCAL. Tells whether the Hardware Clock
           is set to Coordinated Universal Time or local time. You can always
           override this value with options on the hwclock(8) command line.

FILES
       /etc/adjtime

SEE ALSO
       hwclock(8), rtcwake(8)

REPORTING BUGS
       For bug reports, use the issue tracker at
       https://github.com/karelzak/util-linux/issues.

AVAILABILITY
       adjtime_config is part of the util-linux package which can be
       downloaded from Linux Kernel Archive
       <https://www.kernel.org/pub/linux/utils/util-linux/>.

util-linux 2.37.2                 2021-06-02                 ADJTIME_CONFIG(5)