The HTTP Time Protocol (HTP) is used to synchronize a computers time with
web servers as reference time source. This program can be used instead
of ntpdate or similar in networks that have a firewall blocking the NTP port.
Htpdate will synchronize the computer time to Greenwich Mean Time (GMT),
using the timestamps from HTTP headers found in web server responses (the
HEAD method will be used to get the information).
Htpdate works through proxy servers. Accuracy of htpdate will be usually
within 0.5 seconds (better with multiple servers).
To allow the snap package to adjust the time you need to connect the
time-control interface after installation and restart the daemon:
snap connect htpdate-daemon:time-control
You can set the list of hosts (default: google.com) to query for time
via a snap setting like:
snap set htpdate-daemon hosts="google.com www.linux.org"
You can also set additional options for the daemon
snap set htpdate-daemon extra-opts="-d"
It is recommended that you disable your hosts ntp time sync mechanism when
The packages for RHEL 8 and RHEL 7 are in each distribution’s respective Extra Packages for Enterprise Linux (EPEL) repository. The instructions for adding this repository diverge slightly between RHEL 8 and RHEL 7, which is why they’re listed separately below.
The EPEL repository can be added to RHEL 8 with the following command: