Time on website is 2 hours ahead or actual time

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1

I have noticed that the time on the website is 2 hours ahead of the actual time the picture was taken. Look at the church clock in this photos for example.

This happens to many (if not all) of my sequences. When I look the jpeg the time is correct. Nice way to get an alibi though :wink: (I was not there…I was cycling)

1 Like
2

I guess you have UTC+1 normally and +2 with daylight saving time.
I guess the problem lies there

3

Can you explain that please?
I have the same “issue” (not that I care much about it), see Mapillary
In the exif tags it says
DateTime - 2017:05:11 11:42:32
DateTimeOriginal - 2017:05:11 11:42:32
DateTimeDigitized - 2017:05:11 11:42:32
GPSTimeStamp - 9 42 33

The time of the photo is CEST (+2), the GPS time is (UTC/GMT). Mapillary’s time is even +4 UTC, 13:42. So this doesn’t make sense to me.

4

Same with me, only +7 hours

6

I have noticed the same behavior with my sequences which are having DateTime tags set with timezone adjustment (e.g. UTC+2).
I’ve did some tests and can confirm the this is probably a viewer bug.
Sequence/ photo time shown in the app is taking DateTime tag and ADDING your timezone offset from local windows setting.

So, assuming you have 10:00:00 in GPS tag (UTC), and 12:00:00 in DateTime (UTC+2) and you local PC timezone is the same (UTC+2) the time shown will be DateTime + local timezone offset, or 14:00:00 in this specific example.

You can try it yourself - just change your local windows setting to another timezone, reload a page and you will see the date is changed accordingly

I guess this was done by design but I believe the logic should be changed, instead of reading DateTime tag, mapillary viewer should read GPS DateTime tag which is always in UTC.
In that case time in the viewer will be always shown in local timezone of the PC correctly.

If the logic is to keep time shown matching the realtime of the photo, e.g. 10:00:00 irrespective whether it being opened in London or in Tokyo - than probably image DateTime tag should be parsed without any adjustments from mapillary viewer. The downside of this approach is that DateTime EXIF is not always matching actual time of the place where photo was taken. I personally often adjust all my DateTime tags to UTC before processing and uploading.

7

Hi @gpsmapper - I just responded to you by email but just so this thread is updates as well, I’ve let the devs about this. They’ve updated our web apps to show exact time/date from the backend without converting to user local time. I think this should now correct this behavior. If you see any cases of this still happening, let me know. Thanks!

8

Hi @Brenna , it seems the issue has been re-intriduced with API v3>v4 migration.
As far as I can see, date/time shown in the webapp now again uses local computer tz offset added to DateTimeOriginal.

9

let me give you an example:
sequence:

first image (sequence start ) is shown on my laptop (UTC+3) as 7:08 PM (19:08)
DateTimeTaken in the first image is 16:08:02 (already UTC+3)
Source image: 20210630150626_006350.MP4_000093.jpg - Google Drive

Expected behaviour: Mapillary web takes/shows DateTimeTaken as-is (16:08)
Current behavior: Mapillary web applies UTC offset from local client timezone.
Obviously this will work ONLY if DateTimeTaken is recorded in UTC which is normally not the case.