The package net-misc/chrony (NTP daemon replacement) has an initscript which allows you to start the chronyd daemon at boot. The initscript correctly has "need net" in the dependencies, but it should probably have "use dns" as well. My server has dnsmasq on startup which provides DNS to the subnet; dnsmasq needs to be started before chronyd since otherwise chronyd can't look up its hosts.
wout, please place a metadata.xml file in there as well
Good point. Added.