Jet Lag Jet Lag runs invisibly in the background to automatically change your Mac's timezone. Do yourself a favor and never worry about your clock again. Jet Lag uses Skyhook Wi-Fi Positioning System to accurately determine your location. Jet Lag updates your timezone in iCal too, so you're always on time for your appointments. Growl notifications will notify you when your timezone is updated. in Public bookmarkswith clockmacsoftwaresystem_utilitiestimezone