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Daylight Savings Time


thcri

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This may have been talked about but I just noticed my Garmin GPSmap60cs is an hour ahead in time? I have the latest software? Any suggestions on how to change. I have turned it off and back on hoping it would reset itself but it does not.

Menu/menu/setup/time/Daylight savings time - no

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Why not menu/menu/setup/time/Daylight Saving Time - auto?

Worked for me.

It will work now. My unit does not recognize the new DST and changed too soon.

 

Thanks everyone. I just thought it was always automatic depending on where you are. I thought in the past when crossing time zones it even changed automatically for me like the new Cell Phones. It is now working.

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Why not menu/menu/setup/time/Daylight Saving Time - auto?

Worked for me.

It will work now. My unit does not recognize the new DST and changed too soon.

 

Thanks everyone. I just thought it was always automatic depending on where you are. I thought in the past when crossing time zones it even changed automatically for me like the new Cell Phones. It is now working.

 

As I understand it, cell phones change time as you cross from one time zone to another because they get their time info from the local towers. GPSr use UTC (GMT,Zulu) time off the satellites, so you have to tell it what time zone to use.

 

VinceD

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As I understand it, cell phones change time as you cross from one time zone to another because they get their time info from the local towers. GPSr use UTC (GMT,Zulu) time off the satellites, so you have to tell it what time zone to use.

 

VinceD

 

Maybe I'm over-simplifying, but it seems to me the GPSR ought to be able to switch to the local time zone automatically once it determines its position. All that would be needed is where the time zone boundaries are. What am I missing?

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It's way more complicated than it may seem at first. Since compliance with DST is determined by the localities and can be changed at anytime, the software would have to be constantly updated to accomplish this. It took a lot of programming just to get the last changes to DST coded into all the firmware for all the units.

 

But probably more importantly, from a practical stand point with users, it would create great complications. Suppose you were in the Eastern time zone and plotted a course into the Mountain Time Zone and the GPS unit indicated at the start of the trip that you should arrive at 4pm, many users would be confused as to which 4pm the unit meant.

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As I understand it, cell phones change time as you cross from one time zone to another because they get their time info from the local towers. GPSr use UTC (GMT,Zulu) time off the satellites, so you have to tell it what time zone to use.

 

VinceD

 

Maybe I'm over-simplifying, but it seems to me the GPSR ought to be able to switch to the local time zone automatically once it determines its position. All that would be needed is where the time zone boundaries are. What am I missing?

Cell towers get their time from GPS sats as well. Look at any cell tower and you will see several GPS antennea on them. So why does cell towers provide local time and GPS units don't automatically? Because cell towers aren't going anywhere. Everytime you get a signal from a cell tower it and your phone are local. A gps unit will provide DST automatically, but not the time zone because it is mobile and highly so. Say you are flying from Seattle to DC, if your GPS switched with each time zone crossed, your departure time and ETA would change three times over the four time zones, all different. Really, I prefer to make this minor adjustment myself at my pleasure, chooseing which zone to use. If I am on a ship they use zulu time no matter where they are in the world.

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I also believe that in earlier days, when GPS memory was at a premium, the memory overhead to store all the time zone info was thought to be not worth the candle. They could add this to the firmware on x units that have plenty of unused base memory, but it probably isnt very high on Garmin's list of priorities.

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