Why don't GPS units know the time zone??????

Pinecone

Pinecone

En-Route
Joined
May 24, 2022
Messages
4,384
Location
MD
Display Name
Display name:
Pinecone
So, one of the data fields on my GTN-650Xi is ETA in LCL time.

But the LCL time is not the local time at the destination, but the local time based on the GMT offset you set in settings.

So if you take off in Easter time zone, for a destination in Central, it shows you ETA in Eastern time.

WHY???

The GPS knows the location of the destination. It can be programmed with the time zones. And it can be programmed with the DST/ST dates.
 
I don't think the GPS knows the time zone map. You just set the offset. It always uses that to calculate Local time.
 
The question is why doesn't it have time zone maps? This is the type of thing that computers (and a GPS system is mainly a computer) do.

Sometimes you need to know things in local time. Most of the world does not go by UTC.
 
Pinecone said:
So, one of the data fields on my GTN-650Xi is ETA in LCL time.

But the LCL time is not the local time at the destination, but the local time based on the GMT offset you set in settings.

So if you take off in Easter time zone, for a destination in Central, it shows you ETA in Eastern time.

WHY???

The GPS knows the location of the destination. It can be programmed with the time zones. And it can be programmed with the DST/ST dates.
Click to expand...
So it doesn't get Jet Lag?:rofl:
 
Pinecone said:
The question is why doesn't it have time zone maps? This is the type of thing that computers (and a GPS system is mainly a computer) do.

Sometimes you need to know things in local time. Most of the world does not go by UTC.
Click to expand...

This is why most aviation users use UTC rather than depend on a box to spit out the answer. All the FMS's I use and have used go by UTC.
 
This whole time thing is ridiculous.

There should be a Freedom Meridian and One True Time in the contiguous states. The geographic centre of the contiguous 48 states is Lebanon Kansas (pop. 178).

This is the ideal place to establish the Freedom Meridian because there are few people there to interfere with it. From this place, the True High Noon for all true and free men can be calculated daily by direct solar observation.

It's OTT.
 
Maybe it stays set to local time at the departure airport because the programmers figured the pilot was wearing a watch which would also stay set to that time, until reset after landing? Not always the right assumption, but often correct.

As an aside, I was recently back in Idaho for a bit. Southern Idaho is in Mountain time. Nearby Nevada is Pacific time, but the northern border towns stay with Mountain time as their nearest neighbors are all on Mountain time. So the afternoon we drove to northern Nevada, my iPhone reset to Pacific time when we crossed the border, my wife's iPhone did not. We drove around for maybe an hour, our phones disagreeing the whole time, until we crossed the border back into Idaho when my phone reset and they were again in agreement.

I think we are probably running different versions of the IOS on our phones, but still...weird.
 
"Does Anybody Really Know What Time It Is?"

:dunno:
 
Pinecone said:
The question is why doesn't it have time zone maps? This is the type of thing that computers (and a GPS system is mainly a computer) do.

Sometimes you need to know things in local time. Most of the world does not go by UTC.
Click to expand...
Indiana has historically been a great example of why not over the last 20 years or so.

Apparently, on a county by county basis one could decide to pick Eastern, Central, and DST or no DST, and have flip-flopped multiple times.

Doing business and scheduling business meetings in the past required a call to the front desk receptionist to ask "What time does your watch show right now".

One more layer of reconciling in software of "what locale has voted for what time scheme" in every county, and matching to GPS coordinates and boundaries, and keeping it all current. I can see why Garmin said no thanks.

Example:

https://thegatewithbriancohen.com/the-strangest-time-zones-in-the-world/

The Time Zone Mess Known as Indiana

My personal experience with time zones in Indiana — a topic which can fill an entire article unto itself — is that I arrived late in the afternoon at the airport which serves Evansville as a passenger aboard an airplane. I rented a car and drove north on United States Highway 41 to a hotel property in Princeton, where I stayed overnight and ensured of the correct time.

The next morning, I drove further north to Vincennes to a client. I parked the car, confident that I arrived 15 minutes early.

“You are 45 minutes late,” one of the employees with whom I was meeting informed me.

Thinking it was a joke, I laughed.

“She is right,” said another employee.

“But how could that be?!?” I replied, confused and disappointed, as I am usually punctual. “The time at the hotel where I stayed is 15 minutes early. I checked and double-checked the time.”

They started laughing. “We observe Eastern time,” one of the employees explained to me — despite Vincennes technically being in the Central Time Zone in the southwestern part of the state near Illinois. “When you crossed the White River on the way here, you crossed the unofficial time zone.”

What?!?​
 
Tarheelpilot said:
No. It’s variable in rate and never static.

Knowing this you’re never late. Always on time.
Anyone claiming otherwise is observing from the wrong frame of reference.
Click to expand...

Correct! I tell people that say they are running late that you are not late until you get there. :)
 
Spring Ford said:
This whole time thing is ridiculous.

There should be a Freedom Meridian and One True Time in the contiguous states. The geographic centre of the contiguous 48 states is Lebanon Kansas (pop. 178).

This is the ideal place to establish the Freedom Meridian because there are few people there to interfere with it. From this place, the True High Noon for all true and free men can be calculated daily by direct solar observation.

It's OTT.
Click to expand...

I am not sure whether you are being hilarious or dead serious. That is a sign of our times.
 
ElPaso Pilot said:
Indiana has historically been a great example of why not over the last 20 years or so.
Apparently, on a county by county basis one could decide to pick Eastern, Central, and DST or no DST, and have flip-flopped multiple times.
Click to expand...

I remember in the 1980s or 1990s visiting a friend in Lousiville KY (EDT) and taking a day trip to Patoka Lake in Indiana (CST). There was a 2-hour time change for driving a few dozen miles.
 
We have a small motorhome with a Mercedes Sprinter chassis. The clock automatically adjusts itself as we drive from one time zone into another, but Mercedes apparently hasn't gotten the memo that Arizona (where we live) doesn't observe DST.
 
Pilawt said:
We have a small motorhome with a Mercedes Sprinter chassis. The clock automatically adjusts itself as we drive from one time zone into another, but Mercedes apparently hasn't gotten the memo that Arizona (where we live) doesn't observe DST.
Click to expand...


Newer vehicles get local time from the nearest cell tower eliminating any administrative headache managing the mish-mash of every changing timezone rules.

It's about the only way of ensuring accurate real time adjustment for timezone. Maintaining a ship board data base introduces liability and extra cost to user to maintain.
 
Last edited:
Then don't call it Local time on the GPS. It is not local, I could put in -7 hours in the East and it would gladly call that local. Local to who???? :)
 
I agree with the OP. Given the things a gps can do, this seems trivial. Just integrate one more line from the supplement.

At the very least, it shouldn’t say “LCL.” When set to UTC -5, is could say “EST (CDT).” That might confuse a lot of people, but at least it’s true, unlike “LCL” when you cross a time zone.
 
Spring Ford said:
This whole time thing is ridiculous.

There should be a Freedom Meridian and One True Time in the contiguous states. The geographic centre of the contiguous 48 states is Lebanon Kansas (pop. 178).

This is the ideal place to establish the Freedom Meridian because there are few people there to interfere with it. From this place, the True High Noon for all true and free men can be calculated daily by direct solar observation.

It's OTT.
Click to expand...

All you true and free men need a sun dial watch.

upload_2023-6-15_10-33-50.jpeg
 
ElPaso Pilot said:
Doing business and scheduling business meetings in the past required a call to the front desk receptionist to ask "What time does your watch show right now".
Click to expand...
…unfortunately because when you ask “what time zone are you in,” the response is often, “what’s a time zone?”:eek:
 
Jesse Saint said:
I don't think the GPS knows the time zone map. You just set the offset. It always uses that to calculate Local time.
Click to expand...

@Pinecone have you tried ETA at Dest instead of ETA?

a3d9f228818c159c017313890109e349.png
 
Daleandee said:
"Does Anybody Really Know What Time It Is?"

:dunno:
Click to expand...
Great - now I've got that tune stuck in my head!


Tarheelpilot said:
No. It’s variable in rate and never static.

Knowing this you’re never late. Always on time.
Anyone claiming otherwise is observing from the wrong frame of reference.
Click to expand...

  • So.... the faster one travels, the slower that person's internal clock runs vs a stationary person.
  • Thus, the stationary person's clock will be faster, and would reach a point on a clock sooner than the traveling person.
  • Therefore, if I'm running late to a meeting, I should drive slower.
 
Last edited:
Is this what we've come to?

What's next? Complaining that your car doesn't automatically start and turn on the heat/AC 5 minutes before you want to leave so the car is comfortable when you get in?
 
ElPaso Pilot said:
Indiana has historically been a great example of why not over the last 20 years or so.

Apparently, on a county by county basis one could decide to pick Eastern, Central, and DST or no DST, and have flip-flopped multiple times.

Doing business and scheduling business meetings in the past required a call to the front desk receptionist to ask "What time does your watch show right now".

One more layer of reconciling in software of "what locale has voted for what time scheme" in every county, and matching to GPS coordinates and boundaries, and keeping it all current. I can see why Garmin said no thanks.

Example:

https://thegatewithbriancohen.com/the-strangest-time-zones-in-the-world/

The Time Zone Mess Known as Indiana

My personal experience with time zones in Indiana — a topic which can fill an entire article unto itself — is that I arrived late in the afternoon at the airport which serves Evansville as a passenger aboard an airplane. I rented a car and drove north on United States Highway 41 to a hotel property in Princeton, where I stayed overnight and ensured of the correct time.

The next morning, I drove further north to Vincennes to a client. I parked the car, confident that I arrived 15 minutes early.

“You are 45 minutes late,” one of the employees with whom I was meeting informed me.

Thinking it was a joke, I laughed.

“She is right,” said another employee.

“But how could that be?!?” I replied, confused and disappointed, as I am usually punctual. “The time at the hotel where I stayed is 15 minutes early. I checked and double-checked the time.”

They started laughing. “We observe Eastern time,” one of the employees explained to me — despite Vincennes technically being in the Central Time Zone in the southwestern part of the state near Illinois. “When you crossed the White River on the way here, you crossed the unofficial time zone.”

What?!?​
Click to expand...
The really weird thing about Indiana is that the locals seem to be only aware of their own time zone/setting….
Being from nearby Michigan, I’ve made a habit of always asking the local time when making appointments in Indiana. The response I get 9 times out of 10 is a puzzled response of, “The time is the time”, like the local time is the ONLY time on the planet, and we all set our watches to local Indiana time.
 
donjohnston said:
Is this what we've come to?

What's next? Complaining that your car doesn't automatically start and turn on the heat/AC 5 minutes before you want to leave so the car is comfortable when you get in?
Click to expand...


1). Yea, this is a “first world problem” LOL. It could actually be beneficial to remind you of current vs departure time to keep you aware of elapsed time in flight - so you don’t run out of gas.

2) Car automatically cools and heats prior to your entry? Some high end cars already atomically crack the window and sunroof when too hot. Even closes if detects rain.
 
WDD said:
1). Yea, this is a “first world problem” LOL. It could actually be beneficial to remind you of current vs departure time to keep you aware of elapsed time in flight - so you don’t run out of gas.

2) Car automatically cools and heats prior to your entry? Some high end cars already atomically crack the window and sunroof when too hot. Even closes if detects rain.
Click to expand...
Some cars also adjust the environmental controls prior to your drive, but I believe they all require you to schedule your drive ahead of time so they are aware of the need.
 
Until AI is installed. Then it will know when you’re coming. It will be called the Christine AI package. What could go wrong?
 
WDD said:
It could actually be beneficial to remind you of current vs departure time to keep you aware of elapsed time in flight - so you don’t run out of gas.
Click to expand...

I actually thought about that but remembered that pilot's are too smart to be stupid enough to run out of gas ... :mad2:
 
WDD said:
1). Yea, this is a “first world problem” LOL. It could actually be beneficial to remind you of current vs departure time to keep you aware of elapsed time in flight - so you don’t run out of gas.
Click to expand...

you mean like the system the 767 had (gimli glider)?
 
Bob Noel said:
you mean like the system the 767 had (gimli glider)?
Click to expand...
That actually wasn't a time problem as much as pounds / Kilogram understanding. In the same spirit of the metric / standard misunderstanding that burned up a billion dollar Mars spacecraft. :)

Maybe Garmin can in addition to converting to current time zone can also convert your pounds to KG, or whatever.
 
It can also help on long flights to see what your arrival time is WRT sunset and FBO closing times.
 
You must log in or register to reply here.
Back
Top