Metadata: Incorrect Handling of UTC Time Zone

[dror3go]

Using 211010 release, I've noticed wrong time shown for some older photos I have.

For example, the following is info about a photo taken at 2015-05-17 23:02:46:

exiftool -n -j 20150517_230246.jpg | grep Create
  "CreateDate": "2015:05:17 23:02:46",

PhotoPrism shows as if the photo was taken at 2015-05-18 02:02:46, with UTC time shown as 2015-05-17 23:02:46.

An example of a newer photo with correct time in PhotoPrism 2021-08-01 09:38:43:

exiftool -n -j IMG_20210801_093842.jpg | grep Create
  "CreateDate": "2021:08:01 09:38:43",

I'm not sure what other information might be relevant here.
If needed, I can send you private links to the photos.

[lastzero]

Is the time zone UTC or is the UTC time wrong? Could be an estimate based on photos taken at a similar time. You can turn this off in Settings.

[dror3go]

Both UTC & local time are wrong in the UI. The timezone itself is correct.
The correct local timestamp of this specific example should be 2015-05-17 23:02:46 and the correct UTC time should be 2015-05-17 20:02:46.
I have no photos taken around 2:00 AM that day, so I don't think that this is the case. What is the time window for estimating time using other photos around that time? FYI it seems that all the photos from around that time are with wrong local & UTC time.

I do have a video taken with the same device (Samsung Galaxy S3) a couple of hours before the photos: the video is shown with correct date & time - I guess thanks on the fix in #1388.

[lastzero]

About +/- a day. Does the image have a location (GPS)? If not and it has now a time zone out of nowhere, it's an estimate.

[lastzero]

AVC, MP4 & MOV videos are in UTC by default as that's what the standard says.

[dror3go]

The image has a location which I manually set in PhotoPrism, so the Country, Latitude & Longitude are all marked with a V in the photo editing section.

[lastzero]

@graciousgrey Is the information provided enough for you to reproduce / test this?

[graciousgrey]

@dror3go It would be great if you could send us an example photo with the correct time and the one that is not working. We will delete them after testing :)

[dror3go]

@graciousgrey I've sent an email to you guys 🙏

[graciousgrey]

Thank you! I will have a look today :)

[graciousgrey]

Ok this is probably a bug on our side.

There is a video without GPS information with
"CreateDate": "2015:05:17 17:48:22"
and jpg without GPS information with
"DateTimeOriginal": "2015:05:17 23:02:46", "CreateDate": "2015:05:17 23:02:46",

The current behaviour is the following:

After initial indexing we see:

• video --> Local Time: 17:48, UTC Time: 17:48, Time Zone: UTC
• jpg --> Local Time: 23:02, UTC Time: 23:02, Time Zone: Local Time

After I manually set coordinates :

• video --> Local Time: 17:48, UTC Time: 14:48, Time Zone: Asia/Jerusalem --> This is needs to be optimized
• jpg --> Local Time: 23:02, UTC Time: 20:02, Time Zone: Asia/Jerusalem --> This is correct

After optimization (in the background or complete re-index):

• video --> Local Time: 20:48, UTC Time: 17:48, Time Zone: Asia/Jerusalem --> This is correct
• jpg --> Local Time: 02:02, UTC Time: 23:02, Time Zone: Asia/Jerusalem --> This is wrong

[graciousgrey]

When only setting the country and not the coordinates:

After initial indexing we see:

• video --> Local Time: 17:48, UTC Time: 17:48, Time Zone: UTC
• jpg --> Local Time: 23:02, UTC Time: 23:02, Time Zone: Local Time

After I manually set the country :

• video --> Local Time: 17:48, UTC Time: 17:48, Time Zone: UTC --> This is needs to be optimized
• jpg --> Local Time: 23:02, UTC Time: 23:02, Time Zone: Local Time --> This needs to be optimized

After optimization:

• video --> Local Time: 20:48, UTC Time: 17:48, Time Zone: Asia/Jerusalem --> This is correct
• jpg --> Local Time: 23:02, UTC Time: 20:02, Time Zone: Asia/Jerusalem --> This correct

[graciousgrey]

When setting country + coordinates manually:

After initial indexing we see:

• video --> Local Time: 17:48, UTC Time: 17:48, Time Zone: UTC
• jpg --> Local Time: 23:02, UTC Time: 23:02, Time Zone: Local Time

After I manually set country + coordinates :

• video --> Local Time: 17:48, UTC Time: 14:48, Time Zone: Asia/Jerusalem --> This is needs to be optimized
• jpg --> Local Time: 23:02, UTC Time: 20:02, Time Zone: Asia/Jerusalem --> This is correct

After optimization:

• video --> Local Time: 17:48, UTC Time: 14:48, Time Zone: Asia/Jerusalem --> This is wrong
• jpg --> Local Time: 23:02, UTC Time: 20:02, Time Zone: Asia/Jerusalem --> This correct

[Fylax]

Since I found the same problem in my system, I did some extra researches.
Here what I did:

1. Extracted data with exiftool

$ exiftool -time:all -g1 -a -s DSC_4046.JPG 

---- ExifIFD ----
DateTimeOriginal                : 2021:11:05 16:07:59
CreateDate                      : 2021:11:05 16:07:59
---- Nikon ----
TimeZone                        : +01:00
DaylightSavings                 : No

2. Added photo to originals folder and started index via WebUI

2021-11-05 16:50:10 INFO media: DSC_4046.JPG was taken at 2021-11-05 16:07:59 +0000 UTC (meta)
2021-11-05 16:50:02 INFO metadata: failed parsing GPS coordinates in DSC_4046.JPG (exif)

3. Both Local Time and Time UTC are 16:07:59 as expected
4. After setting GPS coordinates via WebUI (Time Zone and Country detected accordingly) UTC Time is updated correctly
5. I run, through cli, photoprism optimize, purge and cleanup. Times were still correct.
6. After some time doing nothing, some background process changed the dates, resulting in:
   • Local Time: 17:07:59
   • Time UTC: 16:07:59

[Fylax]

Extra info: I had some pictures that I didn't manually geotag yet. Still, they presented the same problem.
Might it be related to face recognition task?

[lastzero]

Estimates should now be effectively prevented if the location was manually changed, even if it was just the country.
Can't reproduce it with these changes. Please test again! 👍

[dror3go]

Thanks so much for fixing this! I didn't get the chance to deploy a preview build and make some tests myself. Guess I'llsI'll see the results once I'll update my production build.
Thanks again!