Overview
After a server is restarted, you may notice that the time is out of sync. The NTP service was not able to set it correctly. That should be fixed before starting the applications.
Information
When a server reboots, it starts reading the hardware clock, which may be out of sync with the software clock, that is synced with NTP. The NTP service may take a while to update the server time, which does not indicate an issue. Please wait some more time for the synchronization to happen.
If it does not happen, check if the network is working properly. If it is not, check with the hardware team or the hardware provider (check ethernet ports, cables, and so on).
Testing
Compare the server time with other servers' time to know if it has been updated.