... the user friendly GPS tool


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Timezone in 2.1
#1
Sad 
Just upgraded to 2.1 (thanks BTW), and noted that a new feature "always displays times in GMT/UTC timezone" and was just wondering why this was done (as it doesn't really make any sense)?

Well, it makes sense in that it's the GPS value exactly and converting to current timezone will not be correct in all situations, but having to add 10 or 11 hours (dependant on DST) is a little frustrating.

Am wondering if it may not be better to add a timezone to the GPS log (for quick and dirty conversions)?

Or is it possible to get the timezone of the track (probably need to be points I guess) and then convert to local (eg http://chrischandler.name/ruby/convertin...timezones/)?

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#2
(31.12.2010, 02:13)scribbly Wrote: Just upgraded to 2.1 (thanks BTW), and noted that a new feature "always displays times in GMT/UTC timezone" and was just wondering why this was done (as it doesn't really make any sense)?

GPS data is always UTC. And I hope with 2.1 all timezone-related bugs are squeezed out of the code. Lots of users complained about them...

(31.12.2010, 02:13)scribbly Wrote: Well, it makes sense in that it's the GPS value exactly and converting to current timezone will not be correct in all situations, but having to add 10 or 11 hours (dependant on DST) is a little frustrating.

Am wondering if it may not be better to add a timezone to the GPS log (for quick and dirty conversions)?

Well, if it would be that easy... but determining the correct timezone for a GPS position and a GMT-time is non-trivial.

(31.12.2010, 02:13)scribbly Wrote: Or is it possible to get the timezone of the track (probably need to be points I guess) and then convert to local (eg http://chrischandler.name/ruby/convertin...timezones/)?

I thought about using http://www.geonames.org/export/web-servi...l#timezone to convert GMT-timezones to local ones. Would you be willing to test and validate the results it produces?
--
Christian
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#3
(31.12.2010, 18:47)routeconverter Wrote: GPS data is always UTC. And I hope with 2.1 all timezone-related bugs are squeezed out of the code. Lots of users complained about them...

I actually compared 2.0 and 2.1 side-by-side (as I couldn't remember what 2.0 did, 2.1 seemed a bit of a shock...) and 2.0 seemed to correctly convert UTC time (in the GPS log) to local time in RC display.

That's where the "didn't make sense" came from Wink

(31.12.2010, 18:47)routeconverter Wrote:
(31.12.2010, 02:13)scribbly Wrote: Or is it possible to get the timezone of the track (probably need to be points I guess) and then convert to local (eg http://chrischandler.name/ruby/convertin...timezones/)?

I thought about using http://www.geonames.org/export/web-servi...l#timezone to convert GMT-timezones to local ones. Would you be willing to test and validate the results it produces?

I certainly would (always willing to help)!

I think another option would be the ability to set the timezone of the file. I think that'd be simpler, could be stored as an .ini next to the file. The only difficulty would be if the one file had various timezoned points in it (how often does that happen?).

Certainly, having the option to access a webservice would be neat (and almost perfect?), but does require www access (so a fallback option would be beneficial anyway??)

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#4
(31.12.2010, 23:53)scribbly Wrote: I think another option would be the ability to set the timezone of the file.

Or set the timezone for all displayed times globally inside Extras/Options...

(31.12.2010, 23:53)scribbly Wrote: Certainly, having the option to access a webservice would be neat (and almost perfect?), but does require www access (so a fallback option would be beneficial anyway??)

It does require internet access like the map, so I guess it's not that limiting. A bigger problem is the webservice itself. It has limitations for the number of requests per day so determining the timezone has to be an operation that the users fires up manually.
--
Christian
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#5
(01.01.2011, 17:28)routeconverter Wrote:
(31.12.2010, 23:53)scribbly Wrote: I think another option would be the ability to set the timezone of the file.

Or set the timezone for all displayed times globally inside Extras/Options...

This assumes all files are from the same timezone?

(01.01.2011, 17:28)routeconverter Wrote:
(31.12.2010, 23:53)scribbly Wrote: Certainly, having the option to access a webservice would be neat (and almost perfect?), but does require www access (so a fallback option would be beneficial anyway??)

It does require internet access like the map, so I guess it's not that limiting. A bigger problem is the webservice itself. It has limitations for the number of requests per day so determining the timezone has to be an operation that the users fires up manually.

That's a nuisance... is it very restrictive? I guess you wouldn't want to do each point in a log file Wink

I guess it could be a menu item: "Add Timezone to track"... does that make it like the option above?
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#6
(01.01.2011, 18:23)scribbly Wrote:
(01.01.2011, 17:28)routeconverter Wrote:
(31.12.2010, 23:53)scribbly Wrote: I think another option would be the ability to set the timezone of the file.

Or set the timezone for all displayed times globally inside Extras/Options...

This assumes all files are from the same timezone?

Yes, this would be a global setting.

(01.01.2011, 18:23)scribbly Wrote: That's a nuisance... is it very restrictive? I guess you wouldn't want to do each point in a log file Wink

Correct. You couldn't do it for each point in every file since the request limit is 50000 per IP address per day.

(01.01.2011, 18:23)scribbly Wrote: I guess it could be a menu item: "Add Timezone to track"... does that make it like the option above?

If I'd add it to the Complement-Menu as Complement->Timezone Dunno if that is obvious for users.
--
Christian
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#7
(01.01.2011, 18:23)scribbly Wrote: I guess it could be a menu item: "Add Timezone to track"... does that make it like the option above?

If I'd add it to the Complement-Menu as Complement->Timezone Dunno if that is obvious for users.
[/quote]

Typically I now add the timezone to the end of the filename... for example 110102 123456 130241 EST.gpx would be the file name, when I am using EST [Eastern Standard Time] and have set the GPS unit to EST. If I am on a cruise, or driving across Canada and the U.S., where the timezone will change during a given trip several times, or during a cruise every night or two, I use GMT or Universal Time Zone instead so that I can sync to the camera I use. I also set the camera's clock to GMT when I am doing that sort of cruising and photography. So for me having the program use GMT and allowing ME to adjust for the correct offset is perfect, however it is done. Note that when the cruise I was on visited Corner Brook, Newfoundland, the SHIP stayed on Atlantic Time and did NOT switch to Newfoundland time, even though there is a 1/2 hour difference between the two. Using GMT solved that problem for me, and NO GPS that I know of can accommodate the sort of nonsense that the ship NOT changing correctly would result in otherwise.

So for me the base needs to be GMT and IF the file name showing the correct time zone can be read and used, that is an alternative way to set the time in the program <grin> as long as it is clearly stated in the rules. I always have that time zone just before the .gpx in my files, FWIW


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#8
I am currently planning a trip from home in Toronto to Sedalia, MO and then to Houston, TX and back home via places such as Memphis, TN and Cincinnati, OH and Buffalo, NY. The time zone will change during the trip, and will do so in the middle of one of the recorded GPS routes that are saved as they are recorded. When someone wants to stick to one time zone per file, how do they propose to handle the file with a change in time zones IN that individual file? If all is GMT you can handle it manually, and there is no good way to handle it inside the GPX file, in my view. GMT is just fine, thank you.
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#9
(22.02.2011, 23:21)RsH Wrote: GMT is just fine, thank you.

I guess that is the summary of your post?
--
Christian
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#10
Please have a look at the latest prerelease I've just uploaded. It contains a new configuration option below Extras/Options... which is set to the default timezone by default. I've got so many questions about timezones that I thought it might be useful to make "display the times in my timezone" the default.

What do you think? Does this make sense? Does it help you?
--
Christian
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