How to force NTPD to update date/time after boot?

Question

The Raspberry Pi lacks a hardware clock. How do I force NTPD to update date/time immediately after every boot?

I'm running Raspbian and the Raspberry Pi is connected using an Ethernet cable.

score 55 · Answer 1 · edited Jan 06 '18 at 12:12

55

After searching around, this method worked for me. As you know, the Raspberry Pi 3 has NTP disabled by default. So by just typing this, the NTP support will be enabled:

sudo timedatectl set-ntp True

Check result with timedatectl status

In case of warning, you may have to run sudo timedatectl set-local-rtc true too.

edited Jan 06 '18 at 12:12

Aurora0001

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answered Jun 15 '17 at 06:08

Ariyankj

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score 45 · Answer 2 · edited Aug 05 '18 at 14:09

45

Do an apt-get install ntpdate .

ntpdate will run when an Ethernet interface is brought up, and set the time from an ntp server (see /etc/default/ntpdate).

If ntpd is running, ntpdate will do nothing, however ntpdate will run prior to ntpd at bootup - so this should work out to set the time at bootup as long as there's an Ethernet connection.

edited Aug 05 '18 at 14:09

slm

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answered Jul 03 '13 at 14:02

nos

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score 44 · Answer 3 · answered May 14 '16 at 16:04

44

If your clock is way off, you may need to force ntp to sync by doing:

sudo /etc/init.d/ntp stop
sudo ntpd -q -g
sudo /etc/init.d/ntp start

answered May 14 '16 at 16:04

Jarrod Sears

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Seamus · Answer 4 · 2023-10-04T06:44:48.063

This question is apparently being "recycled" for some reason, and so it seems appropriate to recycle some old answers also :)

The year is now 2023...

This question was asked in 2013. ntpd was the timekeeping software included in the Raspbian distribution at that time (wheezy). However, that changed with the stretch distribution in 2017 when systemd-timesyncd replaced ntpd. The reasons for this change, and some of the technical tradeoffs were discussed in this old answer for those who are interested in such things.

With respect to the question here, perhaps the most salient point in the current environment (bullseye & onward, post-systemd) is this: If you decide to install ntpd (now ntpsec) under your current Raspbian distribution, you will be required to REMOVE systemd-timesyncd. IOW, Debian has declared other timekeeping services in conflict at the apt package level. This method of conflict resolution required Debian to break systemd-timesyncd out as a separate package (apart from systemd), and declare a virtual package called time-daemon. (See REFERENCE)

Note that this method of conflict resolution is (may be) unique to Debian-based distros such as raspbian, and has been fairly recently developed. During an earlier time (e.g. Aug 2018), systemd-timesyncd would "excuse itself" by checking for the presence of other NTP daemons. Earlier versions of the config file for systemd-timesyncd (listed via systemctl cat systemd-timesyncd) included the following ConditionFileIsExecutable statements:

# Under earlier (e.g. Aug 2018) releases of raspbian:
$ systemctl cat systemd-timesyncd

Note the last few lines of the ouput listing:

# don't run timesyncd if we have another NTP daemon installed
ConditionFileIsExecutable=!/usr/sbin/ntpd
ConditionFileIsExecutable=!/usr/sbin/openntpd
ConditionFileIsExecutable=!/usr/sbin/chronyd
ConditionFileIsExecutable=!/usr/sbin/VBoxService

In other words: systemd-timesyncd checks to see if any of these alternative time services are running on your system, and if so, politely defers to them for providing your timekeeping services. It is left to the reader to decide whether the Debian method of conflict resolution is superior or inferior to using the ConditionFileIsExecutable statements.

"force" `ntpd` to update after boot?!

This was the OP's question. The answer (in 2023) hasn't changed: It shouldn't be necessary to do this on any RPi system - unless someone has changed the default configuration! You can verify this as follows:

$ timedatectl
               Local time: Wed 2021-01-13 00:25:33 GMT
           Universal time: Wed 2021-01-13 00:25:33 UTC
                 RTC time: n/a
                Time zone: Europe/London (GMT, +0000)
System clock synchronized: yes
              NTP service: active
          RTC in local TZ: no

Note two items:

System clock synchronized: yes
NTP service: active

Item 1. tells you your system clock is synchronized with whatever the default time source is, and Item 2. is nearly true in that RPi uses the SNTP protocol by default instead of NTP (REF); i.e. this means RPi has a time source, and it is using it.

I think that's all that's needed for an up-to-date answer for 2023, except this: read man timedatectl to learn more about its capabilities.

score 20 · Answer 5 · answered May 21 '16 at 19:47

If you set the Time Zone in raspi-config the Raspberry Pi will automatically update the time on boot, if connected to the internet.

sudo raspi-config
Select Internationalisation Options
Select I2 Change Timezone
Select your Geographical Area
Select your nearest City
Select Finish
Select Yes to reboot now

score 13 · Answer 6 · edited Dec 11 '16 at 13:38

See forum post Time does not sync on Pi 3 and with official dongle.

ntpd emits IP/UDP packets with the ToS field set to 0xc0. So that is quite similar to the other issue I (and many others) have with Raspberry Pi3 when operated over a Wi-Fi internal interface.

As a workaround, add the command

/sbin/iptables -t mangle -I POSTROUTING 1 -o wlan0 -p udp --dport 123 -j TOS --set-tos 0x00

to the file

/etc/rc.local

before the exit 0 line. Next, reboot and check.

score 8 · Answer 7 · answered Jul 03 '13 at 03:55

It should already be updating the time. The NTPD server should start just after the swap file and before SSHD.

Check your /etc/ntp.conf file to make sure it is configured.

It should list at least one server. I use time.nrc.ca for my server.

Manual page for ntp.conf is here: http://linux.die.net/man/5/ntp.conf

score 4 · Answer 8 · answered Jan 07 '20 at 21:52

I had a similar problem with a Pi not syncing. None of these solutions worked. Turns out my network environment was blocking the NTP port (123). The solution for me was

sudo apt install htpdate

taken from: https://www.raspberrypi.org/forums/viewtopic.php?t=222236

Which updates the system clock through HTTP calls instead.

deLabe · Answer 9 · 2017-01-14T03:13:26.790

My son's Rasberry Pi would not update the time out of the box and after trying all the suggestions above I could get it to update manually but not automatically. Finally after looking elsewhere as well without success, I found that the ntp.conf file that came with the Rasberry Pi had the following lines commented out:

#restrict 127.0.0.1
#restrict ::1

I used

sudo nano /etc/ntp.conf

in the terminal to edit the ntp conf file to now be:

# Local users may interrogate the ntp server more closely. 
restrict 127.0.0.1
restrict ::1

That solved the problem for us. It updates with both the WiFi and the ethernet cable. I don't know if it would update with WiFi without the change to rc.local suggested above, as by the time I found the solution above I had already made that change and I have not undone it.

score 3 · Answer 10 · answered Feb 17 '19 at 19:13

You don't need to use ntp to solve the issue. There is a script that reads the date from a server and you only need set the date to be the result of that script (your Raspberry Pi needs to be connected to the internet). Then, you need to run that command at startup.

Step1: Retrieve the date from a server.

sudo date -s "$(wget -qSO- --max-redirect=0 google.com 2>&1 | grep Date: | cut -d' ' -f5-8)Z"

Step2: Run the command at startup by adding it to the file /etc/rc.local (Worked on Ubuntu 16.04).

sudo gedit /etc/rc.local

CREDITS:

1- https://askubuntu.com/a/655528/572294

2- https://askubuntu.com/a/1199/572294

score 2 · Answer 11 · edited Feb 23 '17 at 07:15

2

I found the timedatectl application to help me when I was having a similar issue. It's installed by default and '--help' gives a pretty good and simple overview of how to use the tool.

Note: make sure your timezone is set properly, which this tool can do as well.

edited Feb 23 '17 at 07:15

tlhIngan

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answered Feb 23 '17 at 05:16

adam parsons

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slm · Answer 12 · 2018-08-10T12:25:00.393

This is the approach I ended up taking. Many of these answers seemed to indicate things that just didn't check out when I looked at my Raspian system:

$ cat /etc/os-release
PRETTY_NAME="Raspbian GNU/Linux 9 (stretch)"
NAME="Raspbian GNU/Linux"
VERSION_ID="9"
VERSION="9 (stretch)"
ID=raspbian
ID_LIKE=debian
HOME_URL="http://www.raspbian.org/"
SUPPORT_URL="http://www.raspbian.org/RaspbianForums"
BUG_REPORT_URL="http://www.raspbian.org/RaspbianBugs"

I had nothing that appeared in logs indicating that timedatectl was doing anything, or that ntp was syncing on the NIC's up state, or that NTPD was even installed/configured.

In the end I merely added this to my /etc/rc.local:

$ cat /etc/rc.local
logger "Beginning force syncing NTP..."
service ntp stop
ntpd -gq
service ntp start
logger "Finished force syncing NTP..."

And installed ntp:

$ sudo apt-get install ntp

Which results in this in /var/log/syslog:

Aug  5 09:10:20 pi-hole ntp[526]: Starting NTP server: ntpd.
Aug  5 09:10:20 pi-hole ntpd[555]: proto: precision = 1.458 usec (-19)
Aug  5 09:10:20 pi-hole ntpd[555]: Listen and drop on 0 v6wildcard [::]:123
Aug  5 09:10:20 pi-hole ntpd[555]: Listen and drop on 1 v4wildcard 0.0.0.0:123
Aug  5 09:10:20 pi-hole ntpd[555]: Listen normally on 2 lo 127.0.0.1:123
Aug  5 09:10:20 pi-hole ntpd[555]: Listen normally on 3 eth0 192.168.1.85:123
Aug  5 09:10:20 pi-hole ntpd[555]: Listen normally on 4 lo [::1]:123
Aug  5 09:10:20 pi-hole ntpd[555]: Listen normally on 5 eth0 [fe80::f5ea:7663:4ec:784d%2]:123
Aug  5 09:10:20 pi-hole ntpd[555]: Listening on routing socket on fd #22 for interface updates
Aug  5 09:10:21 pi-hole ntpd[555]: ntpd exiting on signal 15 (Terminated)
Aug  5 09:10:21 pi-hole ntp[661]: Stopping NTP server: ntpd.
Aug  5 09:10:21 pi-hole ntpd[674]: ntpd 4.2.8p10@1.3728-o Sat Mar 10 18:03:33 UTC 2018 (1): Starting
Aug  5 09:10:21 pi-hole ntpd[674]: Command line: ntpd -gq
Aug  5 09:10:21 pi-hole ntpd[674]: proto: precision = 0.625 usec (-21)
Aug  5 09:10:21 pi-hole ntpd[674]: Listen and drop on 0 v6wildcard [::]:123
Aug  5 09:10:21 pi-hole ntpd[674]: Listen and drop on 1 v4wildcard 0.0.0.0:123
Aug  5 09:10:21 pi-hole ntpd[674]: Listen normally on 2 lo 127.0.0.1:123
Aug  5 09:10:21 pi-hole ntpd[674]: Listen normally on 3 eth0 192.168.1.85:123
Aug  5 09:10:21 pi-hole ntpd[674]: Listen normally on 4 lo [::1]:123
Aug  5 09:10:21 pi-hole ntpd[674]: Listen normally on 5 eth0 [fe80::f5ea:7663:4ec:784d%2]:123
Aug  5 09:10:21 pi-hole ntpd[674]: Listening on routing socket on fd #22 for interface updates
Aug  5 09:10:34 pi-hole ntpd[674]: Soliciting pool server 198.98.57.16
Aug  5 09:10:35 pi-hole ntpd[674]: Soliciting pool server 74.82.59.149
Aug  5 09:10:36 pi-hole ntpd[674]: Soliciting pool server 23.131.160.7
Aug  5 09:10:36 pi-hole ntpd[674]: Soliciting pool server 52.37.26.163
Aug  5 09:10:36 pi-hole ntpd[674]: Soliciting pool server 204.2.134.163
Aug  5 09:10:36 pi-hole ntpd[674]: Soliciting pool server 96.126.100.203
Aug  5 09:10:36 pi-hole ntpd[674]: Soliciting pool server 199.223.248.101
Aug  5 09:10:36 pi-hole ntpd[674]: Soliciting pool server 66.228.42.59
Aug  5 09:10:36 pi-hole ntpd[674]: Soliciting pool server 208.75.89.4
Aug  5 09:10:37 pi-hole ntpd[674]: Soliciting pool server 204.2.134.164
Aug  5 09:10:37 pi-hole ntpd[674]: Soliciting pool server 104.236.116.147
Aug  5 09:10:38 pi-hole ntpd[674]: Soliciting pool server 204.9.54.119
Aug  5 09:10:48 pi-hole ntpd[674]: ntpd: time set +6.769186 s
Aug  5 09:10:49 pi-hole ntpd[853]: ntpd 4.2.8p10@1.3728-o Sat Mar 10 18:03:33 UTC 2018 (1): Starting
Aug  5 09:10:49 pi-hole ntpd[853]: Command line: /usr/sbin/ntpd -p /var/run/ntpd.pid -g -u 111:114
Aug  5 09:10:49 pi-hole ntp[844]: Starting NTP server: ntpd.
Aug  5 09:10:49 pi-hole ntpd[856]: proto: precision = 0.625 usec (-21)
Aug  5 09:10:49 pi-hole ntpd[856]: Listen and drop on 0 v6wildcard [::]:123
Aug  5 09:10:49 pi-hole ntpd[856]: Listen and drop on 1 v4wildcard 0.0.0.0:123
Aug  5 09:10:49 pi-hole ntpd[856]: Listen normally on 2 lo 127.0.0.1:123
Aug  5 09:10:49 pi-hole ntpd[856]: Listen normally on 3 eth0 192.168.1.85:123
Aug  5 09:10:49 pi-hole ntpd[856]: Listen normally on 4 lo [::1]:123
Aug  5 09:10:49 pi-hole ntpd[856]: Listen normally on 5 eth0 [fe80::f5ea:7663:4ec:784d%2]:123
Aug  5 09:10:49 pi-hole ntpd[856]: Listening on routing socket on fd #22 for interface updates
Aug  5 09:10:49 pi-hole root: Finished force syncing NTP...

score 0 · Answer 13 · answered Jan 15 '20 at 16:26

I found this somewhere on the interwebs. Seems to work on Buster:

sudo timedatectl set-ntp false && sudo timedatectl set-time "$(date --iso-8601=seconds | cut -d "+" -f1 | tr T ' ')" && sudo timedatectl set-ntp true

I'm not sure if the intermediate command (set-time) is really needed.

score 0 · Answer 14 · answered May 06 '21 at 22:26

Ok, so I did timedatectl and got everything looking fine.

But my raspberry pi never syncs clock when it is wrong. Typical problem scenario for me:

restore SD card from backup
boot is very slow
problems with ssh, ssl certificates
eventually realise the clock is wrong (showing the time approx when the backup was created).
try running various ntpd commands
eventually give up and set clock manually.

When I looked at it before, it seemed that some of the network startup was failing or not working properly because of the wrong clock, and this was interfering with clock sync.

What I would like is a way to force nptd to ignore all certificate expiry etc and just force an update of the clock, and for this to be something that reliably happens during boot, however far out the clock is.

I don't think this question is answered.

score 0 · Answer 15 · answered Jul 26 '21 at 03:46

I solved that in /etc/rc.local by adding at the end (before any exit 0):

sleep 10
ntpdate -u tempus1.gum.gov.pl > /dev/null

Sleep is needed because of starting Ethernet connection. Then immediately Pi synces date and time on each boot.

Check if you have rc.local service first (run at boot) as some of the recent systems lack it. If it does not exist - add it.

Also you can put the below in /etc/crontab:

59 */3  * * *   root    ntpdate -u tempus1.gum.gov.pl > /dev/null

score 0 · Answer 16 · answered Jan 16 '19 at 02:21

0

I use the following on the default image to sync time without installing additional packages:

timedatectl set-local-rtc 0
timedatectl set-ntp 1
timedatectl status

answered Jan 16 '19 at 02:21

Wu Haa

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1

How to force NTPD to update date/time after boot?

16 Answers16

The year is now 2023...

"force" `ntpd` to update after boot?!

Linked

Related

How to force NTPD to update date/time after boot?

16 Answers16

The year is now 2023...

"force" ntpd to update after boot?!

Linked

Related

"force" `ntpd` to update after boot?!