NTP sync is performed every time the controller reboots — unless if you had set NTP sync option to Off. Another reason it can’t perform NTP sync would be if your router cannot access Internet, or if you’d set static IP but didn’t set the correct gateway (i.e. router IP), such that the controller will send NTP request but cannot receive the response.
Firmware 1.8.2 is a while back, so I can’t quite remember how to set a date/time manually — I believe it allows you to do so through the web interface.