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List of Top Public Time Servers

Google Public NTP [AS15169]:

time.google.com

time1.google.com

time2.google.com

time3.google.com

time4.google.com

Cloudflare NTP [AS13335]:

time.cloudflare.com

Facebook NTP [AS32934]:

time.facebook.com

time1.facebook.com

time2.facebook.com

time3.facebook.com

time4.facebook.com

time5.facebook.com

Microsoft NTP server [AS8075]:

time.windows.com

Apple NTP server [AS714, AS6185]:

time.apple.com

time1.apple.com

time2.apple.com

time3.apple.com

time4.apple.com

time5.apple.com

time6.apple.com

time7.apple.com

time.euro.apple.com

DEC/Compaq/HP:

clepsydra.dec.com/clepsydra.labs.hp.com/clepsydra.hpl.hp.com/usno.labs.hp.com

NIST Internet Time Service (ITS) [AS49, AS104]:

time-a-g.nist.gov

time-b-g.nist.gov

time-c-g.nist.gov

time-d-g.nist.gov

time-a-wwv.nist.gov

time-b-wwv.nist.gov

time-c-wwv.nist.gov

time-d-wwv.nist.gov

time-a-b.nist.gov

time-b-b.nist.gov

time-c-b.nist.gov

time-d-b.nist.gov

time.nist.gov

time-e-b.nist.gov

time-e-g.nist.gov

time-e-wwv.nist.gov

utcnist.colorado.edu

utcnist2.colorado.edu

VNIIFTRI:

Stratum 1:

ntp1.vniiftri.ru

ntp2.vniiftri.ru

ntp3.vniiftri.ru

ntp4.vniiftri.ru

ntp.sstf.nsk.ru

ntp1.niiftri.irkutsk.ru

ntp2.niiftri.irkutsk.ru

vniiftri.khv.ru

vniiftri2.khv.ru

Stratum 2:

ntp21.vniiftri.ru

Mobatime:

Stratum 1:

ntp.mobatime.ru

NTP SERVERS:

ntp0.ntp-servers.net

ntp1.ntp-servers.net

ntp2.ntp-servers.net

ntp3.ntp-servers.net

ntp4.ntp-servers.net

ntp5.ntp-servers.net

ntp6.ntp-servers.net

ntp7.ntp-servers.net

Stratum 1:

ntp1.stratum1.ru

ntp2.stratum1.ru

ntp3.stratum1.ru

ntp4.stratum1.ru

ntp5.stratum1.ru

Stratum 2:

ntp1.stratum2.ru Москва

ntp2.stratum2.ru

ntp3.stratum2.ru

ntp4.stratum2.ru

ntp5.stratum2.ru

Stratum1:

Stratum 1:

stratum1.net

time.in.ua:

Stratum 1:

ntp.time.in.ua

ntp2.time.in.ua

Stratum 2:

ntp3.time.in.ua

Company Delfa Co. Ltd. [AS8915]:

ntp.ru

ACO.net [AS1853]:

ts1.aco.net

ts2.aco.net

Berkeley [AS25]:

Stratum 1:

ntp1.net.berkeley.edu

ntp2.net.berkeley.edu

Georgia State University [AS10631]:

ntp.gsu.edu

University of Saskatchewan [AS22950]:

tick.usask.ca

tock.usask.ca

NSU [AS3335]:

Stratum 2:

ntp.nsu.ru

ITAEC [AS41783]:

ntp.psn.ru

RSU [AS47124]:

Stratum 1:

ntp.rsu.edu.ru

National Institute of Information and Communications Technology [AS9355]:

ntp.nict.jp

NTT [AS2914]:

x.ns.gin.ntt.net

y.ns.gin.ntt.net

HE.net [AS6939]:

clock.nyc.he.net

clock.sjc.he.net

TRC Fiord [AS28917]:

ntp.fiord.ru

Netnod NTP service [AS57021]:

Stratum 1:

Göteborg:

gbg1.ntp.se

gbg2.ntp.se

Malmö:

mmo1.ntp.se

mmo2.ntp.se

Stockholm:

sth1.ntp.se

sth2.ntp.se

Sundsvall:

svl1.ntp.se

svl2.ntp.se

Anycast address for nearest NTP server of the above:

ntp.se

QiX NTP [AS14086]:

ntp.qix.ca

ntp1.qix.ca

ntp2.qix.ca

YYCIX NTP [AS396515]:

ntp.yycix.ca

MSK-IX NTP [AS43832]:

Stratum 1:

ntp.ix.ru

Hetzner Online [AS24940]:

ntp1.hetzner.de

ntp2.hetzner.de

ntp3.hetzner.de

Trabia-Network [AS43289]:

time-a.as43289.net

time-b.as43289.net

time-c.as43289.net

RIPE [AS3333]:

ntp.ripe.net

Internet Systems Consortium [AS1280]:

clock.isc.org (prev ntp.isc.org)

TimeNL/SIDN Labs [AS1140]:

ntp.time.nl (ntp1.time.nl)

Kantonsschule Zug [AS34288]:

ntp0.as34288.net

ntp1.as34288.net

INTERNET MULTIFEED CO. [AS7521]:

ntp1.jst.mfeed.ad.jp

ntp2.jst.mfeed.ad.jp

ntp3.jst.mfeed.ad.jp

Chinese Academy of Sciences Nation Time Service Center [AS4808, AS9808, AS23724]:

ntp.ntsc.ac.cn

Nat Morris [AS30746]:

Stratum 1:

ntp.nat.ms

NTP Pool:

pool.ntp.org

0.pool.ntp.org

1.pool.ntp.org

2.pool.ntp.org

3.pool.ntp.org

europe.pool.ntp.org

0.europe.pool.ntp.org

1.europe.pool.ntp.org

2.europe.pool.ntp.org

3.europe.pool.ntp.org

asia.pool.ntp.org

0.asia.pool.ntp.org

1.asia.pool.ntp.org

2.asia.pool.ntp.org

3.asia.pool.ntp.org

ru.pool.ntp.org

0.ru.pool.ntp.org

1.ru.pool.ntp.org

2.ru.pool.ntp.org

3.ru.pool.ntp.org

north-america.pool.ntp.org

0.north-america.pool.ntp.org

1.north-america.pool.ntp.org

2.north-america.pool.ntp.org

3.north-america.pool.ntp.org

0.gentoo.pool.ntp.org

1.gentoo.pool.ntp.org

2.gentoo.pool.ntp.org

3.gentoo.pool.ntp.org

0.arch.pool.ntp.org

1.arch.pool.ntp.org

2.arch.pool.ntp.org

3.arch.pool.ntp.org

0.fedora.pool.ntp.org

1.fedora.pool.ntp.org

2.fedora.pool.ntp.org

3.fedora.pool.ntp.org

0.opensuse.pool.ntp.org

1.opensuse.pool.ntp.org

2.opensuse.pool.ntp.org

3.opensuse.pool.ntp.org

0.centos.pool.ntp.org

1.centos.pool.ntp.org

2.centos.pool.ntp.org

3.centos.pool.ntp.org

0.debian.pool.ntp.org

1.debian.pool.ntp.org

2.debian.pool.ntp.org

3.debian.pool.ntp.org

0.askozia.pool.ntp.org

1.askozia.pool.ntp.org

2.askozia.pool.ntp.org

3.askozia.pool.ntp.org

0.freebsd.pool.ntp.org

1.freebsd.pool.ntp.org

2.freebsd.pool.ntp.org

3.freebsd.pool.ntp.org

0.netbsd.pool.ntp.org

1.netbsd.pool.ntp.org

2.netbsd.pool.ntp.org

3.netbsd.pool.ntp.org

0.openbsd.pool.ntp.org

1.openbsd.pool.ntp.org

2.openbsd.pool.ntp.org

3.openbsd.pool.ntp.org

0.dragonfly.pool.ntp.org

1.dragonfly.pool.ntp.org

2.dragonfly.pool.ntp.org

3.dragonfly.pool.ntp.org

0.pfsense.pool.ntp.org

1.pfsense.pool.ntp.org

2.pfsense.pool.ntp.org

3.pfsense.pool.ntp.org

0.opnsense.pool.ntp.org

1.opnsense.pool.ntp.org

2.opnsense.pool.ntp.org

3.opnsense.pool.ntp.org

0.smartos.pool.ntp.org

1.smartos.pool.ntp.org

2.smartos.pool.ntp.org

3.smartos.pool.ntp.org

0.android.pool.ntp.org

1.android.pool.ntp.org

2.android.pool.ntp.org

3.android.pool.ntp.org

0.amazon.pool.ntp.org

1.amazon.pool.ntp.org

2.amazon.pool.ntp.org

3.amazon.pool.ntp.org

Other:

.mil:

tick.usno.navy.mil

tock.usno.navy.mil

ntp2.usno.navy.mil

.edu:

utcnist.colorado.edu

utcnist2.colorado.edu

timekeeper.isi.edu

rackety.udel.edu

mizbeaver.udel.edu

otc1.psu.edu

gnomon.cc.columbia.edu

navobs1.gatech.edu

navobs1.wustl.edu

now.okstate.edu

ntp.colby.edu

ntp-s1.cise.ufl.edu

bonehed.lcs.mit.edu

level1e.cs.unc.edu

tick.ucla.edu

tick.uh.edu

.com:

ntpstm.netbone-digital.com

nist1.symmetricom.com

ntp.quintex.com

ntp1.conectiv.com

tock.usshc.com

.net:

t2.timegps.net

gps.layer42.net

ntp-ca.stygium.net

sesku.planeacion.net

ntp0.nl.uu.net

ntp1.nl.uu.net

navobs1.oar.net

ntp-galway.hea.net

.org:

ntp1.ona.org

ntp.your.org

ntp.mrow.org

.de:

time.fu-berlin.de

ntps1-0.cs.tu-berlin.de

ntps1-1.cs.tu-berlin.de

ntps1-0.uni-erlangen.de

ntps1-1.uni-erlangen.de

ntp1.fau.de

ntp2.fau.de

ntp.dianacht.de

zeit.fu-berlin.de

ptbtime1.ptb.de

ptbtime2.ptb.de

rustime01.rus.uni-stuttgart.de

rustime02.rus.uni-stuttgart.de

.nl:

chime1.surfnet.nl

ntp.vsl.nl

.at:

asynchronos.iiss.at

.cz:

ntp.nic.cz

time.ufe.cz

.pl:

ntp.fizyka.umk.pl

tempus1.gum.gov.pl

tempus2.gum.gov.pl

.ro:

ntp1.usv.ro

ntp3.usv.ro

.se:

timehost.lysator.liu.se

time1.stupi.se

.ca:

time.nrc.ca

clock.uregina.ca

.mx:

cronos.cenam.mx

ntp.lcf.mx

.es:

hora.roa.es

minuto.roa.es

.it:

ntp1.inrim.it

ntp2.inrim.it

.be:

ntp1.oma.be

ntp2.oma.be

.hu:

ntp.atomki.mta.hu

.eus:

ntp.i2t.ehu.eus

.ch:

ntp.neel.ch

.cn:

ntp.neu.edu.cn

.jp:

ntp.nict.jp

.br:

ntps1.pads.ufrj.br

.cl:

ntp.shoa.cl

.int:

time.esa.int

time1.esa.int

http://support.ntp.org/bin/view/Servers/StratumOneTimeServers

http://support.ntp.org/bin/view/Servers/StratumTwoTimeServers

http://support.ntp.org/bin/view/Servers/NTPPoolServers

http://www.pool.ntp.org/zone/@

http://www.pool.ntp.org/zone/asia

http://www.pool.ntp.org/zone/europe

http://www.pool.ntp.org/zone/north-america

http://www.pool.ntp.org/zone/oceania

http://www.pool.ntp.org/zone/south-america

https://time.nl/

https://time.nl/index_en.html

http://time.in.ua/

https://www.chrony.eu/status

https://www.ntp-server.de/ntp-server-deutschland/

https://www.ntp-server.de/ntp-server-oesterreich/

https://www.ntp-server.de/ntp-server-schweiz/

@sam910037
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sam910037 commented Jan 5, 2022

Taiwan National Time and Frequency Standard Laboratory
Telecommunication Laboratories (TL)
Chunghwa Telecom Co., Ltd.

tock.stdtime.gov.tw
watch.stdtime.gov.tw
time.stdtime.gov.tw
clock.stdtime.gov.tw	
tick.stdtime.gov.tw

@cadusilva
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cadusilva commented Jan 16, 2022

hello, here are some NTP servers located in Brazil. Those are Stratum 1 servers.

NTP.br

gps.ntp.br
a.st1.ntp.br
b.st1.ntp.br
d.st1.ntp.br

Brazilian National Observatory

ntp.on.br
ntp2.on.br

Federal University of Rio de Janeiro

ntps1.pads.ufrj.br
ntps1.cortex.pads.ufrj.br

University of São Paulo

lrte.ntp.ifsc.usp.br

Update: it's not responding anymore, maybe they took it down.

I am also hosting a NTP server. Mine (Bolha NTP) is coupled with a GPS dongle, so it's a Stratum 1 time server and it's NTS-ready using port 4460, everything powered by Chrony.

Alto NTP Server

time.bolha.one

@catleeball
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OpenWRT also operates NTP servers:

0.openwrt.pool.ntp.org
1.openwrt.pool.ntp.org
2.openwrt.pool.ntp.org
3.openwrt.pool.ntp.org

@hype8912
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Ubiquiti time servers

0.ubnt.pool.ntp.org
1.ubnt.pool.ntp.org
2.ubnt.pool.ntp.org
3.ubnt.pool.ntp.org

@rail01
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rail01 commented Jul 10, 2022

I made a separate gist with Polish NTP servers only and their details, I'm more than fine with my list being copied here: https://gist.github.com/rail01/290b2f0fd87f3d11cb38f8836f66bb4d

@mdavids
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mdavids commented Oct 11, 2022

TimeNL (ntp.time.nl) is a pool nowadays, consisting of ntp1.time.nl and ntp2.time.nl (see https://time.nl).
Also, there are two NTS-capable systems available; ntppool1.time.nl and ntppool2.time.nl.

@racooper
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ntppub.tamu.edu is a valid public time source as well.

@tazboyz16
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https://www.he.net/adm/ntp.html -- HE has three public NTP servers

@ravench
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ravench commented Jan 2, 2023

https://www.metas.ch/metas/en/home/fabe/zeit-und-frequenz/time-dissemination.html

The Swiss Federal Institute of Metrology
Laboratory Photonics, Time and Frequency runs it's own time / atomic clock and offers three public NTP servers.

METAS operates three public stratum 1 NTP servers in open access policy, namely: 

ntp11.metas.ch
ntp12.metas.ch
ntp13.metas.ch

The alias ntp.metas.ch points to one of the above servers.

@mqudsi
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mqudsi commented Jan 10, 2023

The recently-added-to-the-list time.cloudflare.com is a stratum 3 server/pool and probably useless for most.

mqudsi@freebsd> ntpdate -q time.cloudflare.com
server 2606:4700:f1::123, stratum 3, offset -0.000278, delay 0.03026
server 2606:4700:f1::1, stratum 3, offset -0.000490, delay 0.02956
server 162.159.200.123, stratum 3, offset -0.000189, delay 0.03023
server 162.159.200.1, stratum 3, offset -0.000497, delay 0.02959

@cygvis
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cygvis commented Jan 10, 2023

Could somebody ELI5 what "stratum" is for me and anybody else that doesn't know?

Is it something I can use on a home network? If not, what's the best public server in the US/NA?

@cadusilva
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cadusilva commented Jan 10, 2023

Could somebody explain what "stratum" is for me and anybody else that doesn't know?

The stratum indicates how close to the "absolute time" the NTP server is. Zero is the source of time, like a GPS device or atomic clock. Stratum 1 is the server that connects to the absolute clock source (stratum 0) and provides its time info to other clients and servers. Stratum 2 is a server that gets its time info from the stratum 1 server. Stratum 3 gets its time from a stratum 2 server and so on until stratum 16 when clients and servers don't trust the time provided. There are others stratum levels but you get the idea.

@cygvis here I use a GPS USB dongle as time source for my local network and also to the NTP Pool. The middleman is a Chrony server that gets the time from the GPS and provides a stratum 1 public time server.

@cygvis
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cygvis commented Jan 11, 2023

@cadusilva Oh okay, that makes more sense. Do you or does anybody know what stratum Google and Apple time servers are?

@cadusilva
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@cygvis you can check the stratum of any NTP time server using this service.

@cygvis
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cygvis commented Jan 11, 2023

@cadusilva nice tool thanks. Looks like they're both Stratum 1

@cadusilva
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@cygvis just be aware that Google (and Facebook) uses leap smearing. Using them both together or with other servers that don't use leap smearing can cause unexpected clock corrections or failure to sync, according to Red Hat.

@mqudsi
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mqudsi commented Jan 11, 2023

Apple’s pool is a mix of stratum 1 and stratum 2. Depends on which server you end up with.

@rail01
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rail01 commented Feb 12, 2023

EPIX, Polish non-commercial Internet Exchange and IP transit operator hosts ntp.epix.net.pl

@n1zyy
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n1zyy commented Mar 1, 2023

Note that all the *.openwrt.pool.ntp.org, *.ubnt.pool.ntp.org, *.centos.pool.ntp.org, etc. names are just vendor zones and don't actually point to distinct pools of servers. My understanding is that this is done to allow some rough mapping of traffic (via DNS) from each vendor, and maybe to allow them to turn off a vendor zone if they pull a Netgear or D-Link and ship what turns out to be a terribly buggy NTP implementation that egregiously abuses servers.

It doesn't really make sense to try configuring other vendor's pool.ntp.org names because they all just point to the same global pool of servers.

@pnahco
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pnahco commented May 8, 2023

.ir (Iran)

ir.pool.ntp.org
server3.ir.pool.ntp.org
ntp.day.ir

@user8446
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Ubuntu uses ntp.ubuntu.com

@Lofty73
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Lofty73 commented Jun 6, 2023

Hi thanks. It seems to be an ongoing issue with me. Everything works perfect except the time server issue.
Will give it a try when I have rebuilt my dead PC

@vescudero
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In Spain, we have several Stratum 1:

  • ntp.roa.es (pool composed by hora.roa.es and minuto.roa.es)
  • nts1.roa.es (NTS Authentication)
  • ntp1.software.imdea.org
  • server ntp.i2t.ehu.es
  • hora.cica.es

@hakiran16
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time.day.ir

@keilamohan
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I am trying to connect to some stratum 1 international time servers (currently located in the US), but it seems I am not reaching any of them. I was able to connect to ones in the US. Does anyone know why this may be happening?

@hvia
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hvia commented Jul 26, 2023

NTP / NTS server free to use worldwide (better performance for western Europe), located in France, stratum-2 :
ntp.viarouge.net

see its info page @ http://ntp.viarouge.net

@ziptx
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ziptx commented Aug 14, 2023

Great list. Would be really helpful to know which entries hold to the leap smearing standard. Regular NTP and smeared servers should not be mixed together.

https://developers.cloudflare.com/time-services/ntp/ [no smearing]
https://developers.google.com/time/smear [smearing]
https://engineering.fb.com/2020/03/18/production-engineering/ntp-service/ [smearing]

@gdriggs
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gdriggs commented Aug 14, 2023 via email

@PRSXFENG
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PRSXFENG commented Mar 3, 2024

National Institute of Information and Communications Technology, Japan has a NTP server at

ntp.nict.jp

Source: https://www.nict.go.jp/en/sts/ntp.html

PS, my Brother printer connects to sntp.brother.com for NTP which appears to just CNAME to the above mentioned NTP Server

the FAQ section of NICT's NTP server also directs you to Internet Multifeed Co. which also runs a few NTP servers
https://www.mfeed.ad.jp/ntp/detail.html

ntp.jst.mfeed.ad.jp

ntp1.jst.mfeed.ad.jp
ntp2.jst.mfeed.ad.jp
ntp3.jst.mfeed.ad.jp

ntp1.v6.mfeed.ad.jp
ntp2.v6.mfeed.ad.jp
ntp3.v6.mfeed.ad.jp

@CroZg
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CroZg commented Mar 16, 2024

Croatia .hr:

Stratum 1
ntp.hr dynamic IP
time1.ntp.hr 161.53.78.71
time2.ntp.hr 161.53.78.72

Stratum 2
os.ntp.carnet.hr Osijek
ri.ntp.carnet.hr Rijeka
st.ntp.carnet.hr Split
zg1.ntp.carnet.hr Zagreb
zg2.ntp.carnet.hr Zagreb

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