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Reading GPX timestamps in mapping programs
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Terry Pinnell
Oct 2, 2011, 6:57:46 AM10/2/11
to
OT in uk.rec.walking but I know there are several mapping experts there,
and hopefully on-topic in the other groups.
--------------------
Could someone set me straight on a basic point please?
GPX files contain timestamps in UTC time (what I call GMT, being rather
old).
After importing these (or the original proprietary GPS-recorded 'MMO'
files) into my particular mapping program, Memory-Map, the time at any
point on a walk can be read out conveniently by hovering over it with the
mouse cursor. Handy for quickly pin-pointing where I stopped for lunch,
when I got back, etc.
No problem for a UK walk, as at worst it's an hour wrong. But for walks in
faraway locations the arithmetic gets tedious (especially if it involves a
date change).
In Mem-Map there appears to be no way to adjust this to local time.
Is this the case with other map apps please? Or (like the excellent GPS
Utility which I use for editing/conversion) do they have a simple way to
adjust?
--
Terry, East Grinstead, UK
and hopefully on-topic in the other groups.
--------------------
Could someone set me straight on a basic point please?
GPX files contain timestamps in UTC time (what I call GMT, being rather
old).
After importing these (or the original proprietary GPS-recorded 'MMO'
files) into my particular mapping program, Memory-Map, the time at any
point on a walk can be read out conveniently by hovering over it with the
mouse cursor. Handy for quickly pin-pointing where I stopped for lunch,
when I got back, etc.
No problem for a UK walk, as at worst it's an hour wrong. But for walks in
faraway locations the arithmetic gets tedious (especially if it involves a
date change).
In Mem-Map there appears to be no way to adjust this to local time.
Is this the case with other map apps please? Or (like the excellent GPS
Utility which I use for editing/conversion) do they have a simple way to
adjust?
--
Terry, East Grinstead, UK
OG
Oct 2, 2011, 9:15:09 AM10/2/11
to
pc to match the local time?
Craig Wallace
Oct 2, 2011, 12:51:29 PM10/2/11
to
On 02/10/2011 11:57, Terry Pinnell wrote:
> Could someone set me straight on a basic point please?
>
> GPX files contain timestamps in UTC time (what I call GMT, being rather
> old).
>
> After importing these (or the original proprietary GPS-recorded 'MMO'
> files) into my particular mapping program, Memory-Map, the time at any
> point on a walk can be read out conveniently by hovering over it with the
> mouse cursor. Handy for quickly pin-pointing where I stopped for lunch,
> when I got back, etc.
>
> No problem for a UK walk, as at worst it's an hour wrong. But for walks in
> faraway locations the arithmetic gets tedious (especially if it involves a
> date change).
>
> In Mem-Map there appears to be no way to adjust this to local time.
>
> Is this the case with other map apps please? Or (like the excellent GPS
> Utility which I use for editing/conversion) do they have a simple way to
> adjust?
You could process the files using GPSBabel, with the "move" filter. This
>
> GPX files contain timestamps in UTC time (what I call GMT, being rather
> old).
>
> After importing these (or the original proprietary GPS-recorded 'MMO'
> files) into my particular mapping program, Memory-Map, the time at any
> point on a walk can be read out conveniently by hovering over it with the
> mouse cursor. Handy for quickly pin-pointing where I stopped for lunch,
> when I got back, etc.
>
> No problem for a UK walk, as at worst it's an hour wrong. But for walks in
> faraway locations the arithmetic gets tedious (especially if it involves a
> date change).
>
> In Mem-Map there appears to be no way to adjust this to local time.
>
> Is this the case with other map apps please? Or (like the excellent GPS
> Utility which I use for editing/conversion) do they have a simple way to
> adjust?
will shift the timestamps by a number of hours (or days / minutes
/seconds).
Technically the GPX files would be incorrect, as they would still have
the UTC time, just offset a bit. But it should display the correct time
in Memory-Map etc anyway.
Or Garmin Mapsource has the option to set an offset from UTC for the
displayed times. Though you would have to change this manually each time
you view tracks in different time zones.
--
Craig Wallace
http://craig.neogeo.org.uk
http://www.neogeo.org.uk
Terry Pinnell
Oct 3, 2011, 4:43:04 AM10/3/11
to
Craig Wallace <craigw84@fast_NOSPAM_mail.fm> wrote:
Thanks both. I realise I can permanently edit/convert or temporarily
adjust the display of the GPX with various tools. But before I email
Mem-Map support to gripe about their program's inflexibility in that
respect, I'd like to know if other mapping programs *do* have such an
adjustment feature.
Phil Cook
Oct 3, 2011, 5:44:10 AM10/3/11
to
On 03/10/2011 09:43, Terry Pinnell wrote:
> Craig Wallace<craigw84@fast_NOSPAM_mail.fm> wrote:
>
>> On 02/10/2011 11:57, Terry Pinnell wrote:
>>> Could someone set me straight on a basic point please?
>>>
>>> GPX files contain timestamps in UTC time (what I call GMT, being rather
>>> old).
>>>
>>> After importing these (or the original proprietary GPS-recorded 'MMO'
>>> files) into my particular mapping program, Memory-Map, the time at any
>>> point on a walk can be read out conveniently by hovering over it with the
>>> mouse cursor. Handy for quickly pin-pointing where I stopped for lunch,
>>> when I got back, etc.
>>>
>>> No problem for a UK walk, as at worst it's an hour wrong. But for walks in
>>> faraway locations the arithmetic gets tedious (especially if it involves a
>>> date change).
>>>
>>> In Mem-Map there appears to be no way to adjust this to local time.
>>>
>>> Is this the case with other map apps please? Or (like the excellent GPS
>>> Utility which I use for editing/conversion) do they have a simple way to
>>> adjust?
>>
>> You could process the files using GPSBabel, with the "move" filter.
> Craig Wallace<craigw84@fast_NOSPAM_mail.fm> wrote:
>
>> On 02/10/2011 11:57, Terry Pinnell wrote:
>>> Could someone set me straight on a basic point please?
>>>
>>> GPX files contain timestamps in UTC time (what I call GMT, being rather
>>> old).
>>>
>>> After importing these (or the original proprietary GPS-recorded 'MMO'
>>> files) into my particular mapping program, Memory-Map, the time at any
>>> point on a walk can be read out conveniently by hovering over it with the
>>> mouse cursor. Handy for quickly pin-pointing where I stopped for lunch,
>>> when I got back, etc.
>>>
>>> No problem for a UK walk, as at worst it's an hour wrong. But for walks in
>>> faraway locations the arithmetic gets tedious (especially if it involves a
>>> date change).
>>>
>>> In Mem-Map there appears to be no way to adjust this to local time.
>>>
>>> Is this the case with other map apps please? Or (like the excellent GPS
>>> Utility which I use for editing/conversion) do they have a simple way to
>>> adjust?
>>
>> You could process the files using GPSBabel, with the "move" filter.
>> Or Garmin Mapsource has the option to set an offset from UTC for the
>> displayed times. Though you would have to change this manually each time
>> you view tracks in different time zones.
>
> Thanks both. I realise I can permanently edit/convert or temporarily
> adjust the display of the GPX with various tools. But before I email
> Mem-Map support to gripe about their program's inflexibility in that
> respect, I'd like to know if other mapping programs *do* have such an
> adjustment feature.
>
It's not available in Oziexplorer. It's a PITA when you are trying to
>> displayed times. Though you would have to change this manually each time
>> you view tracks in different time zones.
>
> Thanks both. I realise I can permanently edit/convert or temporarily
> adjust the display of the GPX with various tools. But before I email
> Mem-Map support to gripe about their program's inflexibility in that
> respect, I'd like to know if other mapping programs *do* have such an
> adjustment feature.
>
figure out where you were at a particular time on a walk.
I keep my camera clocks on UTC/GMT to avoid confusion. But if I am
looking at a track in Ozi to figure out where I took a photo whilst the
computer clock is on BST the times Ozi displays from the track are out
by an hour but they are correct internally.
--
Phil Cook
Terry Pinnell
Oct 3, 2011, 12:53:17 PM10/3/11
to
allows adjustment?
As I mentioned, GPS Utility does, but I don't use it for map viewing, only
for editing & conversion (and occasionally creating elevation charts), so
that doesn't help much.
Bill Bradshaw
Oct 3, 2011, 2:40:23 PM10/3/11
to
I use an Vista HCx. Have you gone into your gps time settings and set
it for the time zone you are in. I download my tracks to OziExplorer
and the track files have the proper time stamp for each of the track
points. I think you can fix your problem for future tracks but you have
to do it in your gps.
--
<Bill>
it for the time zone you are in. I download my tracks to OziExplorer
and the track files have the proper time stamp for each of the track
points. I think you can fix your problem for future tracks but you have
to do it in your gps.
--
<Bill>
Brought to you from Anchorage, Alaska.
Phil Cook
Oct 4, 2011, 7:32:16 AM10/4/11
to
On 03/10/2011 19:40, Bill Bradshaw wrote:
> I use an Vista HCx. Have you gone into your gps time settings and set
> it for the time zone you are in. I download my tracks to OziExplorer
> and the track files have the proper time stamp for each of the track
> points. I think you can fix your problem for future tracks but you have
> to do it in your gps.
The GPS records its timestamps in UTC Ozi then converts them for display.
> I use an Vista HCx. Have you gone into your gps time settings and set
> it for the time zone you are in. I download my tracks to OziExplorer
> and the track files have the proper time stamp for each of the track
> points. I think you can fix your problem for future tracks but you have
> to do it in your gps.
As far as I know if you import a track into Ozi it keeps it in UTC when
you save it as a .plt file. It then displays the time of track points
based on your current PC clock setting.
However, looking at some tracks just now it seems that Ozi has changed.
I have tracks from summer and winter showing the correct local time (GMT
or BST) in the "show track list" window. I know they are all in UTC when
I look at the actual .plt file.
--
Phil Cook
Bill Bradshaw
Oct 4, 2011, 2:48:58 PM10/4/11
to
I forgot. There is a problem with using older tracks with the new
versions of OziExplorer because the way the track date is recorded
changed. There is more info in the OziUsers-L group on
groups.yahoo.com.
versions of OziExplorer because the way the track date is recorded
changed. There is more info in the OziUsers-L group on
groups.yahoo.com.
--
<Bill>
Brought to you from Anchorage, Alaska.
<Bill>
Brought to you from Anchorage, Alaska.
Nigel Cliffe
Oct 6, 2011, 12:42:16 PM10/6/11
to
Phil Cook wrote:
> It's not available in Oziexplorer. It's a PITA when you are trying to
> figure out where you were at a particular time on a walk.
>
> I keep my camera clocks on UTC/GMT to avoid confusion. But if I am
> looking at a track in Ozi to figure out where I took a photo whilst
> the computer clock is on BST the times Ozi displays from the track
> are out by an hour but they are correct internally.
I use EXiFtool (its controlled in a command-line / script manner) to sort
> It's not available in Oziexplorer. It's a PITA when you are trying to
> figure out where you were at a particular time on a walk.
>
> I keep my camera clocks on UTC/GMT to avoid confusion. But if I am
> looking at a track in Ozi to figure out where I took a photo whilst
> the computer clock is on BST the times Ozi displays from the track
> are out by an hour but they are correct internally.
out the discrepancies, it can write the Long/Lat into the photo EXIF data,
having correctly adjusted for any mis-match between camera time and GPS
time. The result is that, the photo file now "knows" where it was taken.
A second pass then creates a Google KML file which will display the GPS
trace and photographs on Google Earth.
- Nigel
--
Nigel Cliffe,
Webmaster at http://www.2mm.org.uk/
RsH
Oct 14, 2011, 9:11:14 AM10/14/11
to
Use RouteConverter, which is a free download. It permits you to set the timezone and then converts UTC to the local time. You need to pick
the location and may need to adjust your pick per DST if that applied at the time, but then the rest is done for you.
the location and may need to adjust your pick per DST if that applied at the time, but then the rest is done for you.
RsH
Terry Pinnell
Mar 10, 2012, 7:28:47 AM3/10/12
to
responding. I'll check out both suggestions.
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