Otázkou je, jestli je to opravdu tvůj problém - a zda ti to jinde funguje:
#ntpdate -d ntp.nic.cz
8 Sep 23:40:03 ntpdate[11359]: ntpdate 4.2.4@1.1437-o Sun Jan 21 16:56:34 UTC 2007 (1)
Looking for host ntp.nic.cz and service ntp
host found : ntp.nic.cz
transmit(217.31.202.100)
receive(217.31.202.100)
transmit(217.31.202.100)
receive(217.31.202.100)
transmit(217.31.202.100)
transmit(217.31.202.100)
transmit(217.31.202.100)
217.31.202.100: Server dropped: strata too high
server 217.31.202.100, port 123
stratum 16, precision -6, leap 11, trust 000
refid [217.31.202.100], delay 0.02798, dispersion 24.00009
transmitted 4, in filter 4
reference time: 00000000.00000000 Thu, Feb 7 2036 7:28:16.000
originate timestamp: e4e3ac33.60637bd0 Wed, Sep 8 2021 23:40:03.376
transmit timestamp: e4e3ac34.5fa1d323 Wed, Sep 8 2021 23:40:04.373
filter delay: 0.02798 0.04373 0.00000 0.00000
0.00000 0.00000 0.00000 0.00000
filter offset: -0.00105 -0.00124 0.000000 0.000000
0.000000 0.000000 0.000000 0.000000
delay 0.02798, dispersion 24.00009
offset -0.001056
8 Sep 23:40:05 ntpdate[11359]: no server suitable for synchronization found
Používej vždy dva servery, pokud možno z jiných sítí. Třeba tik.cesnet.cz.