Waypoint+ has the capability to request time-of-day from a Garmin GPS and SET the time on your PC.
Here is how to proceed:
a) Have your GPS locked to SVs.
b) Put your GPS in GARMIN (sometimes called GARM/GARM or HOST or DATA TRANSFER) mode.
c) Go to the GPS menu
d) Query the UTC time via menu item.
e) You should find your PC set to the correct time.