ntpdig(1) on Linux
The text f3c5656cb1fd, as Debian 10 (Buster) shipped it.
standard Simple Network Time Protocol client program
Flags it lists
-
--authentication -
--concurrent -
--debug-level -
--gap -
--help -
--ipv4 -
--ipv6 -
--keyfile -
--logfile -
--no-wait -
--samples -
--set-debug-level -
--slew -
--step -
--steplimit -
--timeout -
--version -
--wait -
-4 -
-6 -
-D -
-M -
-S -
-a -
-c -
-d -
-g -
-h -
-j -
-k -
-l -
-p -
-s -
-t