Force date/time/clock sync

From terminal:

sudo ntpdate -u time.apple.com

macOS Catalina:

sudo sntp -sS pool.ntp.org

Per the ntpdate man page, the accepted answer will become obsolete when ntpdate is retired. If you encounter this problem, this will do the equivalent:

sudo ntpd -q 

ntpd : ...sets and maintains the system time of day in syn- chronism with Internet standard time servers.

-q : Set the time and quit.

Sources:

• http://www.manpages.info/macosx/ntpdate.8.html
• http://www.manpages.info/macosx/ntpd.8.html

I ran these two commands on Mojave:

sudo systemsetup -setnetworktimeserver pool.ntp.org
sudo sntp -sS pool.ntp.org

Following https://superuser.com/a/1479345 following two answers on https://apple.stackexchange.com/q/117864