Provided by: fake-hwclock_0.9_all bug

NAME

       fake-hwclock - Control fake hardware clock

SYNOPSIS

       fake-hwclock [ command ] [ force ]

BACKGROUND

       Many  embedded  Linux  systems do not have a functional hardware clock.
       Either they simply don't have a hardware clock at all or  they  have  a
       hardware  clock  but  it is not usable (e.g. because Linux doesn't know
       how to use it or because no battery is present).

       This can lead to time moving backwards to  some  default  value  (often
       1970)  when the system is rebooted. Since lots of software assumes that
       time only moves forward this is a bad thing. NTP can (and should  where
       practical)  be  used  to sync with an external timeserver but it is not
       available early in the boot process and may be  unavailable  for  other
       reasons.

       The design expectation of fake-hwclock is that it will be run very late
       at shutdown and very early at boot. This will ensure that  fsck  has  a
       vaguely  sensible  idea  of system time at boot and won't complain that
       the last-modified time in the filesystem is not hugely in the  past  or
       future. Some users may not worry about this too use case, in which case
       it is possible to modify the init system configuration to  move  things
       earlier/later as appropriate.

DESCRIPTION

       fake-hwclock  sets and queries a fake "hardware clock" which stores the
       time in a file. This program may be run  by  the  system  administrator
       directly  but is typically run by init (to load the time on startup and
       save it on shutdown) and cron (to save the time hourly).

       If no command is given then fake-hwclock acts as if  the  save  command
       was used.

COMMANDS

       save   Save  the  time  to the file. If force is specified fake-hwclock
              will  move  the  saved  clock  either  backwards  or   forwards.
              Otherwise it will only move it forwards.

       load   Load  the time from the file. If force is specified fake-hwclock
              will move the clock either backwards or forwards.  Otherwise  it
              will only move it forwards.

FILES

       /etc/fake-hwclock.data
              The file used to store the time

       /etc/init.d/fake-hwclock
              The init script used to run fake-hwclock on startup and shutdown

       /lib/systemd/system/fake-hwclock.service
              systemd service used to run fake-hwclock on startup and shutdown

       /etc/default/fake-hwclock
              Settings file for the init script.

       /etc/cron.hourly/fake-hwclock
              Cron job used to save the time hourly

ENVIRONMENT VARIABLES

       FILE   set the file used by fake-hwclock

RETURN VALUES

       1 is returned for invalid commands. 0 is returned in all other cases.

BUGS

       This  approach  can  only  provide a crude approximation of what a real
       hardware clock provides. Use of NTP or another method to keep the  time
       in sync is strongly advised.