sanyalnet-ntp.freeddns.org stratum-2 /var/etc/ntpd.conf - read more at http://supratim-sanyal.blogspot.com/2017/03/free-public-stratum-2-and-stratum-3-ntp.html

ntpd.conf

#
# pfSense ntp configuration file
#

tinker panic 0
# Orphan mode stratum
tos orphan 16


# Upstream Servers
server time.nist.gov iburst maxpoll 9 prefer
server tick.usno.navy.mil iburst maxpoll 9 prefer
server tock.usno.navy.mil iburst maxpoll 9 prefer
server ntp2.usno.navy.mil iburst maxpoll 9 prefer
server ptbtime1.ptb.de iburst maxpoll 9
server ptbtime2.ptb.de iburst maxpoll 9
server rustime01.rus.uni-stuttgart.de iburst maxpoll 9
server rustime02.rus.uni-stuttgart.de iburst maxpoll 9
server time.apple.com iburst maxpoll 9
server ntps1-0.cs.tu-berlin.de iburst maxpoll 9


statsdir /var/log/ntp
logconfig =syncall +clockall +peerall +sysall
driftfile /var/db/ntpd.drift
restrict default kod limited nomodify noquery nopeer notrap
restrict -6 default kod limited nomodify noquery nopeer notrap
restrict 127.0.0.1 mask 255.0.0.0