NTP Server

ch.pool.ntp.org

europe.pool.ntp.org, https://support.ntp.org/bin/view/Servers/NTPPoolServers

132.163.4.107, ntp-a.boulder.nist.gov

130.60.7.42, UNI Zürich

NIST Internet Time Servers: http://tf.nist.gov/tf-cgi/servers.cgi

time.google.com