The same with ntp:
@client:~# ntpdate aaa.bbb.ccc.188 24 May 12:56:09 ntpdate[26846]: adjust time server aaa.bbb.ccc.188 offset 0.083226 sec
@client:~# ntpdate AAAA:BBBB::188 24 May 12:56:38 ntpdate[27174]: no server suitable for synchronization found
The same with ntp:
@client:~# ntpdate aaa.bbb.ccc.188
24 May 12:56:09 ntpdate[26846]: adjust time server aaa.bbb.ccc.188 offset 0.083226 sec
@client:~# ntpdate AAAA:BBBB::188
24 May 12:56:38 ntpdate[27174]: no server suitable for synchronization found