Linux – How to set current time on Linux

datelinux

Why is the output of the following commands different?

root@vmi2115:/var# hwclock
Sun 26 Jun 2011 01:21:38 PM CEST  -0.273230 seconds
root@vmi2495:/var# date
Sun Jun 26 15:21:39 CEST 2011
root@vmi2115:/var#

And can I change the current time on Linux?

Best Answer

Usually you'll want to have the time set automatically, and in that case, you'll want to set up ntpd to automatically set the time for you.

The specifics differ slightly from distribution to distribution, but if you're running Ubuntu, for instance, there's a guide on setting up NTP on Ubuntu. Otherwise, just Google ntpd <distribution-name>, and you'll probably find it.

If you want to set it manually, however, you can use date --set="<date string>". Examples of this could be:

date --set="23 June 1988 10:00:00"
date --set="10:00:00"

Related Solutions

Linux – How to get the current date according to an NTP server without setting it locally

This Perl script should do what you need (assuming you don't need precision to the 10^-6 of a second):

#!/usr/bin/perl -w

use strict;
use Math::Round;

## Get current date (epoch)
my $date=time();

## Get the seconds offset, rounding to the nearest second
my $ntp=nearest(0.1,`ntpdate -q $ARGV[0] | gawk '(\$NF~/sec/){print \$(NF-1)}'`); 

## Get the server's time
my $ntp_date=$date+$ntp;

## Convert to human readable and print
print "The time according to server $ARGV[0] is " . localtime($ntp_date) . "\n";

Save the script as check_ntp.pl and run it with the server as an argument:

perl ./check_ntp.pl my.ntp.server

Best Answer

Related Solutions

Linux – How to get the current date according to an NTP server without setting it locally

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