OpenNTPD

OpenNTPD - Lightweight NTP server ported from OpenBSD

Emerge
Install OpenNTPD:

OpenRC
Start the ntp daemon:

Add the ntp daemon to the default runlevel:

systemd
OpenNTPD does not work with systemd. See systemd-timesyncd instead.

Configuration
The default configuration file for OpenNTPD:

For further information see :

Client
Alternatively sync the client to a server on the local network:

systemd / timedatectl
systemd comes with to manage the system clock time.

The manpage explains how  and  can work together:

However, it also seems to work if is enabled (DEPRECATED, please use  instead as described below)

The time is synced despite the fact that says NTP sync is off:

But in systemd 213 new feature arrived -. It is a built-in NTP client designed as a part of, and the recommended way to sync time with systemd.