# readclock(8)

    NAME
         readclock - read the AT's real time clock

    SYNOPSIS
         readclock [-nwW2]

    DESCRIPTION
         Readclock reads the AT's real time clock and sets the machine's time.  It
         is  usually  the second thing done in /etc/rc, the first thing is setting
         the time zone by sourcing /etc/profile.  This means  that  the  clock  is
         assumed to tell the wall clock time.  If you want to run the clock in GMT
         then you can put TZ=GMT (or any other TZ value) in front of the readclock
         command.

    OPTIONS

         -n   Play-act, don't set the time nor change the calibration  data,  just
              show what would be done.

         -w   Write the current time to the  CMOS  clock.   Dangerous,  see  BUGS.
              Don't forget to use TZ=GMT in front of readclock if the clock should
              run in GMT.

         -W   Like -w, but also sets the status registers of  the  CMOS  clock  to
              their proper values.  (For if the clock suddenly runs at an odd pace
              or has stopped and the BIOS doesn't repair it.)

         -2,  Add 20 to any year before 2000.  If your CMOS clock year  can't  run
              past  2000,  then  you  can set it to 1980 and use -2 to correct the
              year.  Together with -w the year minus 20 is written to the clock.

    FILES

         /etc/profile        Timezone and other shell initialization code.

    SEE ALSO
         date(1), utime(1).

    BUGS
         Reported to not work on some AT's.

         May mess up the clock royally when setting it (-w).  Only if you  have  a
         very  standard  AT and you are not afraid of having your CMOS setup reset
         to the default with a "checksum error" should you use  readclock  to  set
         the time of the CMOS clock.  You have been warned.

    AUTHOR
         Kees J. Bot (kjb@cs.vu.nl)