Time of mapillary picture is two hours advanced and one second late

[skorbut]

What steps will reproduce the problem?

1. Open ​http://www.mapillary.com/map/im/DUkHJo4JS6mrg3Rez2aZ5g in JOSM

What is the expected result?

The displayed time should be 16:01:07

What happens instead?

The displayed time is 18:01:06

I checked with the originally uploaded file. There seem to be two issues:

1. The displayed time is two hours advanced. Was the UTC-Offset (+1 hour + 1h for DST = +2 hours) added twice? Was (one of) the local-time EXIF field(s) interpreted as UTC time?

2. The displayed time is one second late. Maybe an off-by-one error somewhere?

Both may be problems that occurr at Mapillary. Semi-Offtopic: I wanted to check with Mapillarys data from the API but was unable to do so. APIv1 doesn't seem to return the creation time and for APIv2 I could not get a client_id (see ​https://github.com/mapillary/mapillary_issues/issues/1113 ).

Sorry to bug you again with file creation timestamps...

Please provide any additional information below. Attach a screenshot if possible.

Repository Root: http://josm.openstreetmap.de/svn
Build-Date: 2015-06-22 11:23:21
Last Changed Author: Don-vip
Revision: 8520
Repository UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Relative URL: ^/trunk
URL: http://josm.openstreetmap.de/svn/trunk
Last Changed Date: 2015-06-22 13:20:28 +0200 (Mon, 22 Jun 2015)
Last Changed Rev: 8520

Identification: JOSM/1.5 (8520 en) Linux Ubuntu 15.04
Memory Usage: 262 MB / 3641 MB (57 MB allocated, but free)
Java version: 1.7.0_79, Oracle Corporation, OpenJDK 64-Bit Server VM
Java package: openjdk-7-jre:amd64-7u79-2.5.5-0ubuntu1
VM arguments: [-javaagent:/usr/share/java/jayatanaag.jar]
Dataset consistency test: No problems found

Plugins:
- DirectUpload (31241)
- Mapillary (31284)
- OpeningHoursEditor (31241)
- buildings_tools (31241)
- commons-imaging (31241)
- editgpx (31241)
- imagery_offset_db (31241)
- livegps (31241)
- measurement (31289)
- mirrored_download (31294)
- pbf (31241)
- photo_geotagging (31241)
- poly (31241)
- utilsplugin2 (31241)
- walkingpapers (31241)

Last errors/warnings:
- W: Mappaint style "standard" (FIXME Highlight Warnings) icon "error_small.png" not found.
- E: Failed to locate image 'presets/crossing.png'
- W: Could not get presets icon presets/crossing.png
- E: java.net.UnknownHostException: api.openstreetmap.org
- W: org.openstreetmap.josm.io.OsmTransferException: Could not connect to the OSM server. Please check your internet connection.. Cause: java.net.UnknownHostException: api.openstreetmap.org

[nokutu]

Ok, fixed. The problem was that the program was using my timezone (GMT +2). I just changed it to GMT. Later I will probably add the option to change the timezone. And don't worry about bugging me. The more bugs people find the better the plugin becomes.

I will upload the stable version of the plugin soon. Until then, this will be in the development version.

[skorbut]

I reopened the issue. I hope that's fine with you...

There are still 2 things (tested on ​https://github.com/nokutu/mapillary/blob/master/Mapillary.jar?raw=true just now):

1. When I uploaded ​http://www.mapillary.com/map/im/DUkHJo4JS6mrg3Rez2aZ5g the time was 16:01:07, now the time displayed is 16:01:06. So one second is missing. This is no practical problem but maybe an indication that somewhere something went not as planned (incorrect time conversion somewhere?). I wanted to check at Mapillary myself to see if it's a problem there but don't have access to APIv2. AFAIK time is not displayed in APIv1 and on the website.

2. The time is now displayed as "2015-05-10 - 16:01:06 (GMT)". I was under the assumption that the displayed time should be the local time when the picture was taken (which is around 4 in the afternoon as you can see on the church-clock in the background). The timezone is Zurich (GMT+1) and since it's after March, it's daylight saving time, so the displayed time should be "2015-05-10 - 16:01:06 (GMT+2)". Do you agree?

[nokutu]

About the first part, I've checked the time given by the Mapillary API, it is Sun, 10 May 2015 16:01:06 GMT. Maybe some things happens with the upload, rounding maybe. How do you know the exact time? In the image metadata?. And then, about the timezone. Mapillary doesn't provide me any timezone information, so the only possibilty would be to let the user set the timezone manually. I'll ask the Mapillary team if they can at least write the country where the image was taken, so I can automatically show the time in local timezone.

[floscher]

The time returned from the ​Mapillary API is 2015-05-10T16:01:06.000Z.
That's ​16:01:06 UTC or 18:01:06 UTC+2, so the time is wrong on the Mapillary servers.

So the whole "2 hours and 1 second" thing was introduced either during the upload process or in internal processing on mapillary.com servers.

That having been said, I'm closing this now, because:

• determining the local time at the location the photo has been created is hard (cameras don't save timezone information, EXIF metadata only supports TZ info ​since July 2016; to determine the local timezone later you'd need the TZ borders and info about daylight saving times) and IMHO not worth the effort.
• We display the time correctly as we get it from the server in the local timezone of the user. For the Mapillary website there already exists an issue for this: ​https://github.com/mapillary/mapillary_issues/issues/2349