# ADJTIME_CONFIG(5) - man - phpMan

[ADJTIME_CONFIG(5)](https://www.chedong.com/phpMan.php/man/ADJTIMECONFIG/5/markdown)                           File formats                           [ADJTIME_CONFIG(5)](https://www.chedong.com/phpMan.php/man/ADJTIMECONFIG/5/markdown)



## 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)](https://www.chedong.com/phpMan.php/man/hwclock/8/markdown); and read by programs like
       rtcwake to get RTC time mode.

       The file is usually located in _/etc_, but tools like [**hwclock**(8)](https://www.chedong.com/phpMan.php/man/hwclock/8/markdown) or [**rtcwake**(8)](https://www.chedong.com/phpMan.php/man/rtcwake/8/markdown) 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)](https://www.chedong.com/phpMan.php/man/hwclock/8/markdown) 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)](https://www.chedong.com/phpMan.php/man/hwclock/8/markdown) 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)](https://www.chedong.com/phpMan.php/man/clock/8/markdown)) 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)](https://www.chedong.com/phpMan.php/man/hwclock/8/markdown) command line.

## FILES
       _/etc/adjtime_

## SEE ALSO
       [**hwclock**(8)](https://www.chedong.com/phpMan.php/man/hwclock/8/markdown), [**rtcwake**(8)](https://www.chedong.com/phpMan.php/man/rtcwake/8/markdown)

## 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)](https://www.chedong.com/phpMan.php/man/ADJTIMECONFIG/5/markdown)