Does the 2DS sync the time from any accurate source, like your server?
Setting my clock on the DSC panel is not difficult, but once the panel is IP with your module, perhaps NTP would be a very nice feature request to keep the clock precise, and in sync with DST.
We decided not to include NTP because DSC's panels are synchronized to line frequency (60Hz, 50Hz) which makes their clocks very accurate. The only time it might be useful is if the panel loses power.
We still have the ability to set the clock from the server, that was included in the firmware, we just don't use it on Envisalinks. I'll put it on the list of webserver enhancements that we could add: add a button to "Set System Time".
Thanks for considering. In today's day and age, setting a clock using NTP (or as you suggest a more confined method during your server handshake) is just one of those nice integration things as basic as DHCP... and will guarantee an accurate clock despite the owner (and how accurately they set it). NTP is useful to ensure synced clocks when comparing event logs between different locations/databases, latency of travel, etc.
I was reading a news story just a few weeks ago about how power authorities in the US are considering loosening the requirements on line frequencies to allow drift of upwards of 10%. There was some discussion about how older devices that relied on the 60Hz line frequency for clock maintenance would show equivalent drift.
Personally, I don't think the alarm panel needs to be time-calibrated on a regular basis (like hourly), but a manual button on the website would be helpful to "tweak" once in a while. If/when we start seeing actual drift on the panels, then you can re-think automatic sync.
In the North Eastern power pool (Ontario, New York, Quebec, New England states, and the Canadian Martime provinces), frequency is allowed to deviate by up to 60mHz (0.1%) but any deviation to the positive must later be compensated for in the negative within a 24 hour period. So if you run a little fast in the morning, you have to run an equal time period slow in order to have a "net" frequency of 60Hz over the day. That's why line frequency coordinated clocks are considered pretty accurate.
A change to 10% would be nuts. Maybe they meant an increase of 10%? I know with all the renewables coming online, frequency is harder to manage but that's a huge shift....