Files found under the /etc/chrony/conf.d directory with the .conf suffix are parsed in the lexicographical order of the file names when chronyd starts up. This enables a fragmented configuration of chronyd. Although those files can contain any directives listed in chrony.conf(5), it would be wiser to add NTP sources in the /etc/chrony/sources.d directory. Please read /etc/chrony/sources.d/README for more information.