Changing time servers in High Sierra

man timed and "hoakley " says that timed still uses /etc/ntp.conf and I see nothing in the launchd plist that selects that or anything else, so I would think that it is either hard-coded or in some alternate configuration file. Anyway, in 10.13.6, changing it has no effect on what the pref pane says is being used. And the pref pane only allows one of three Apple servers. Changing that has no effect on ntp.conf  Erasing it causes the USA server to be re-entered (without affecting the file). So, is it possible to point it to a different time server? If so, how?