assume 5.1.6 in newest camera? what's the firmware in the older camera?
answering a question you didn't ask, due to documented un-reliability of time.windows.com I use time.nist.gov but this is not the problem you are having.
I can't use DST in any DS-2CD2x32 because it seems the chinese don't understand DST in fact they have a single timezone for the entire country.
I have all cameras on 5.1.6 at one site and EST/no DST and STILL have different times on the cameras. Time settles down after a camera reboot or two...still wrong (setting no DST yields the correct time until november). Also tried setting CST/with DST no luck. Anyone have better luck?