chrony is a versatile implementation of the Network Time Protocol (NTP). It can synchronise the system clock with NTP servers. Chrony is an accurate network time daemon and an alternate implementation of the Network Time Protocol (NTP) compared to ntp.org's NTPd.
Chrony has quite a few advantages over the other NTP implementations, check the chrony ntp comparison page for more details.
FreeBSD 12 supports Chrony v3.5 which allows privilege separation. The installer will create the user chronyd. So the Chrony daemon will running as the the unprivileged user chronyd