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

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

time.nist.gov
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
utcnist.colorado.edu
utcnist2.colorado.edu

VNIIFTRI:

Stratum 1:

ntp1.vniiftri.ru
ntp2.vniiftri.ru
ntp3.vniiftri.ru
ntp4.vniiftri.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:

Stratum 1:

ntp1.stratum1.ru
ntp2.stratum1.ru
ntp3.stratum1.ru
ntp4.stratum1.ru
ntp5.stratum1.ru

Stratum 2:

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

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
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.or
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:

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

.com:

ntpstm.netbone-digital.com
nist1.symmetricom.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

.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