Garmin have several feature that relate to the time of day . some example be sun & moon time , estimate time of arrival . if you have travel into a different time zone out of you original setting , the GPS unit leave it up to you to calculate the correct time base on you original setting . this be very inconvenient when you have travel from the west coast to the east coast thru four time zone . it also provide a problem when you destination be right on a time zone border . a cell phone automaticly change for time zone , but NOT a GPS unit that can calculate exactly where you be in the world ???? this be a Garmin overlook that I believe they should correct .