ADJTIME_CONFIG(5) - man - phpMan

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)