On Solaris 11.4 NTP does update the time after boot.
By default this can take a few minutes, because the NTP client
waits for a few reply’s of the NTP servers.
To update the time quickly it is recommended to use the ‘burst iburst’
flags in the ntp.conf
server <ntpserverip> burst iburst
Using this configuration NTP adjusts the time a few seconds after start.
This is an important configuration if you start your apps or databases automatically.