On my 2010 GTX, the procedure is
Press Mode Button until Settings displayed. Press the UP or DOWN arrow until CLOCK is visible.
Press the SET button to enter the function. CHANGE CLOCK OFF-SET will be displayed.
Press the UP or DOWN arrow to adjust the clock to the local time.
Press the SET button.
Note: the clock uses GPS, so when setting the clock, all you're changing is the hour.
Hope this helps. Good luck.
Jaybeaux
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