NAME | SYNOPSIS | DESCRIPTION | FILES | SEE ALSO | REPORTING BUGS | AVAILABILITY |
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ADJTIME_CONFIG(5) File formats ADJTIME_CONFIG(5)
adjtime_config - information about hardware clock setting and drift factor
/etc/adjtime
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 adjtime file is formatted 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.
/etc/adjtime
hwclock(8), rtcwake(8)
For bug reports, use the issue tracker at https://github.com/util-linux/util-linux/issues.
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/>. This page
is part of the util-linux (a random collection of Linux
utilities) project. Information about the project can be found at
⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩. If you have
a bug report for this manual page, send it to
[email protected]. This page was obtained from the
project's upstream Git repository
⟨git://git.kernel.org/pub/scm/utils/util-linux/util-linux.git⟩ on
2024-06-14. (At that time, the date of the most recent commit
that was found in the repository was 2024-06-10.) If you discover
any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page,
or you have corrections or improvements to the information in
this COLOPHON (which is not part of the original manual page),
send a mail to [email protected]
util-linux 2.39.594-1e0ad 2023-07-19 ADJTIME_CONFIG(5)
Pages that refer to this page: hwclock(8), rtcwake(8)