Where is the date and time preference data saved on Mac? I need to check programmatically whether Set Date and Time automatically is checked or not on a Mac System Preferences.

I didn't find any .plist file that contained this information, can anybody tell me where I can find this information?
I don't know of a purely programmatic way of getting it, but the systemsetup command can do it:

$ systemsetup -getusingnetworktime
Network Time: On