time setting offset dst ntp

I am sure this topic has been discussed a few times here, but would like to know what most think the best practise is for syncing Dahua IP cameras' time with a Dahua NVR/XVR's time? Should the NVR/XVR be set to sync with an NTP and each IP camera also set to sync with an NTP in the camera's own...

Dealing wih a bizzar error with my Hikvision NVR 7616NI-E2 - for whatever reason, it automatically adds 30 minutes for 3 of my 5 cams with EVERY possible time setting (2 cams display time as set/expected, 3 cams show 30 min more than set/expected). Interestingly enough, one of the 2 cams...