fake-hwclock(8) [debian man page]

FAKE-HWCLOCK(8) 					      System Manager's Manual						   FAKE-HWCLOCK(8)

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.

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.

       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

       /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.

Debian								   5 April 2012 						   FAKE-HWCLOCK(8)