setclock, setclk --
set the system clock or the real-time clock
[ time ]
[ -j | -p | -r | -s ]
[ -t ]
[ -v ]
[ -c rtcdev ]
[ -d allowdiff ]
setclock sets the battery-powered, real-time
time of day clock (RTC) to the given time.
is not given, setclock displays the current RTC
time must be a combination of digits with the form:
CC is the first two digits of the year (00-99),
YY is the last two digits of the year (00-99),
MM is the month (01-12),
DD is the day (01-31),
hh is the hour (00-23),
and mm is the minute (00-59).
If a year is not supplied, it is taken from the current system time.
A drawback of setclock is that the second cannot be
specified, and is always set to 00.
For this reason, you should instead use setclk and
with the -t option to set the RTC
and system clocks.
to set the system time maintained by the kernel from the
RTC at system startup.
setclk can also set the RTC from the system clock;
for example, to update the RTC at changeover to or from
Daylight Saving Time.
setclk takes the following options:
The -j, -p, -r, and -s
options cannot be used together.
Specify the device, rtcdev,
that allows access to the RTC;
the default device is /dev/clock.
If the difference between system and RTC time is less
than or equal to allowdiff seconds, do not reset.
Jump: resynchronize the system time using the difference between when
the time was last set and the current time. This adjusts the time
when a system with Power Management has Resumed after being
in a Frozen state.
Print only: show the RTC and system times and the difference
in seconds between them. Do not change the times.
Set the RTC from the system time.
Set the system time from the RTC. This is the default
action of setclk.
Calls date(C) with the -t flag (which includes the century).
Verbose: show the RTC and system times and the difference
in seconds between them.
Set the system clock to
15:03 on August 26, 2005 using setclock:
Set both the system clock
to 15:03:45 on August 26, 2005
using date (with the -t option),
and use setclk to synchronize the RTC with
the system clock:
date -t 200508261503.45; /etc/setclk -r
At system startup, asktime resynchronizes the
system clock from the RTC
if there is more than one second difference between them:
Reset the RTC from the system clock if there are more
than 1200 seconds between their values:
Not all computers have real-time clocks.
Refer to your computer's hardware reference manual.
The command date `setclock` cannot set the
second in the system clock because
of the granularity of the /dev/clock device.
Use setclk to synchronize the system
clock with the RTC.
device file access to real-time clock
© 2007 The SCO Group, Inc. All rights reserved.
SCO OpenServer Release 6.0.0 -- 12 June 2007