WAAS covers all of the US, so if you are located in the US, having Enhanced ON should be fine. It does take a few minutes to acquire satellites, and once it does the GPS symbol will be solid, not flashing. Grouser gave and explanation of DMS and DM. You might turn the GPS off, and check and see if your time comes up correct. If it is fine, then try each of the GPS ON settings and check the clock to see if either one of those settings make any changes with the time. My machine isn't available to me for a few days, or I would try some things to see if I could find a reason the clock would be incorrect. I run my CTX in the Enhanced and not had any problems with the time being incorrect...........
This isn't related to your time and GPS question, but when you get into the XChange2 App, there are preferences that will need to be set there as well. There is a small black rectangular box in the upper right hand corner of the App screen labeled Preferences. Go into that and set the options there. If you forget to change that to MILES, your info in the App will be in meters and centimeters, not feet and inches. Good Luck with the new machine............HH