NAME

       adjtime - 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; 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) allow to 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  keeps the file /etc/adjtime, that keeps some historical information.  For more details see
       "The Adjust Function" and  "The Adjtime File" sections from hwckock(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 decimal integer.

   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
              command line.

FILES

       /etc/adjtime

SEE ALSO

       hwclock(8), rtcwake(8)

AVAILABILITY

       This    man    page    is    part    of    the    util-linux    package    and    is    available    from
       https://www.kernel.org/pub/linux/utils/util-linux/.

util-linux                                         August 2018                                 ADJTIME_CONFIG(5)