Ttgjyuk

Instead of ntpdate (which is deprecated), use

sudo service ntp stop
sudo ntpd -gq
sudo service ntp start

The -gq tells the ntp daemon to correct the time regardless of the offset (g) and exit immediately (q) after setting the time.

Use sntp to set the time immediately. For example:

sudo sntp -s 24.56.178.140

The numbers after -s can be any ntp time server, that one is NIST in Ft. Collins, Colorado.

As others have pointed out the best solution is to instruct ntpd to ignore the panic threshold, which is 1000 seconds by default. You can configure the panic threshold in one of two ways:

• edit /etc/default/ntp and ensure that the -g option is present.


• edit /etc/ntp.conf and place tinker panic 0 at the top

So far this is essentially what others have recommended however there is one more step I think you should take. Install the fake-hwclock program:

# apt-get install fake-hwclock


fake-hwclock: Save/restore system clock on machines without working RTC hardware

 Some machines don't have a working realtime clock (RTC) unit, or no
 driver for the hardware that does exist. fake-hwclock is a simple set
 of scripts to save the kernel's current clock periodically (including
 at shutdown) and restore it at boot so that the system clock keeps at
 least close to realtime. This will stop some of the problems that may
 be caused by a system believing it has travelled in time back to
 1970, such as needing to perform filesystem checks at every boot.

 On top of this, use of NTP is still recommended to deal with the fake
 clock "drifting" while the hardware is halted or rebooting.

With fake-hwclock installed your machine will not start up thinking it is 1970 all over again. When your machine boots up it will set its clock to the timestamp fake-hwclock wrote during the last reboot/shutdown. This means you can have a somewhat correct clock in case there are network issues when you boot up.

ntpdate is a program different from the net dameon. NTPDate is probably erroring out on boot because ntpd is running on that socket.

From the command line, run

# sudo service ntp stop ; sudo ntpdate -s time.nist.gov ; sudo service ntp start

You could also uninstall ntpd all together (apt-get remove ntp) and add a cron script to use ntpdate every hour or so.

UPDATE

ntp service probably won't have meaningful value for you on this system, so remove that first.

# sudo apt-get remove ntp

Now add the command:

ntpdate -sb time.nist.gov

to /etc/rclocal

Reboot. Should be good at that point.

rdate -s tick.greyware.com

if all you want to do is set the clock once, simple

The correct way to do this on a Debian / Mint / Ubuntu (or other Debian derivative) system is to have the line

NTPD_OPTS="-g"

in the file

/etc/default/ntp

This ensures that when ntpd is started from the /etc/init.d/ntp script, it runs with the "-g" option, viz

 start-stop-daemon --start --quiet --oknodo --pidfile /var/run/ntpd.pid --startas /usr/sbin/ntpd -- -p /var/run/ntpd.pid -g -u 124:128

to allow ntpd to correct the system time when it is more than 1000 s out, eg when the system time is January 1st 1970 on startup because there is no hardware RTC.

Try using the -b option to step the time.

tlsdate sets the local clock by securely connecting with TLS to remote servers and extracting the remote time out of the secure handshake. Unlike
ntpdate, tlsdate uses TCP, for instance connecting to a remote HTTPS or TLS
enabled service, and provides some protection against adversaries that try to
feed you malicious time information.

$ tlsdate -V -n -H encrypted.google.com

Use timedatectl (systemd service unit) to set the time. ntp is deprecated.

sudo systemctl restart systemd-timesyncd.service

You can check the time was updated reading the logs with journalctl -xe | tail

Reference

• Ubuntu Server documentation


• Freedesktop


• man timesyncd.conf

Well,

I am running a raspbian (debian wheezy) on my raspberry pi, which doesn't have the hwclock. I found it handy to write a little script and run it after my internet interface is up, so that I am sure that the moment the network becomes available, the clock gets updated.

First check that you have the ntpdate package by running

sudo apt-get update
sudo apt-get install ntpdate

You need to add the following into your /etc/network/interfaces (surely eth0 here is just an example):

auto eth0
 iface eth0 inet dhcp
 post-up /usr/local/sbin/update-time.sh

And create the following script in /usr/local/sbin/update-time.sh (don't forget to make it executable by chmod):

#!/bin/bash
# This script checks if the ntp process is running, stops it, updates the system time, starts it again

ps cax | grep -c ntpd > /dev/null
onoff=$?
if [ "$onoff" -gt 0 ]; then
 echo "stopping ntpd..."
 service ntp stop
 echo "ntpd stopped"
else
 echo "ntpd not running, ready to update the date"
fi


isinstalled=$(dpkg-query -l | grep -c ntpdate)
if [ "$isinstalled" -gt 0 ]; then
 ntpdate -t 3 -s ntp4.stratum2.ru
 echo "date and time update executed"
else
 echo "ntpdate package not installed, can't update using ntp"
fi

echo "restarting ntpd..."
service ntp start 
echo "ntpd running"
echo "printing current date and time:"
date

exit

Note that some current Ubuntu based systems don't even use the NTP service by default now. On my Linux Mint 19 (Ubuntu 18.04) machine, time is kept by systemd-timesyncd.

So to get an up to date time after it has lost sync, I just run

sudo systemctl restart systemd-timesyncd

Since 15.04 Ubuntu uses systemd by default. Therefore critical systems like time are managed through systemd. To find what service your system is using run something like

systemctl list-unit-files | grep -E 'ntp|timesyncd'

For TechJS on 16.04 the service was ntp. For myself on Ubuntu 18.04 (Mint 19) the service is systemd-timesyncd. Interestingly, I logged into a 16.04 server I have and it uses systemd-timesyncd as well.

The ntpd algorithms discard sample offsets exceeding 128 ms, unless the interval during which no [absolute value of] sample offset is less than 128 ms exceeds 900s. The first sample after that, no matter what the offset, steps the clock to the indicated time. In practice this reduces the false alarm rate where the clock is stepped in error to a vanishingly low incidence.

Normally, ntpd exits if the offset exceeds the sanity limit, which is 1000 s by default. This can be turned off with the -g option:

-g
Normally, ntpd exits if the offset exceeds the sanity limit, which is 1000 s by default. If the sanity limit is set to zero, no sanity checking is performed and any offset is acceptable. This option overrides the limit and allows the time to be set to any value without restriction; however, this can happen only once. After that, ntpd will exit if the limit is exceeded. This option can be used with the -q option.

both from http://doc.ntp.org/4.1.0/ntpd.htm

-Jonathan Natale

If you are on systemd you could use this command:

sudo systemctl restart ntp
# or
sudo systemctl restart ntp.service

And then the time gets updated within near 10-15 seconds.

Tested on ubuntu mate 16.04

ntpd and ntpdate run by default using a restricted port (UDP 123). If you are behind a firewall, ntpd will never work, but ntpdate can work with the -u option. For example: ntpdate -u 0.ubuntu.pool.ntp.org or ntpdate -u time.nist.gov should both work fine.

If you can afford the time to wait whatever time it takes before your system gets in sync, you can use the ntp-wait command:

ntp-wait || exit -1 
# i believe this would exit the script if it fails, but not sure of ntp-wait return codes, learn this first.

echo Time is synced, go ahead with backup
tar
rsync etc.