Canon CR3 files - dates

[FreddyFremad]

Hi,

First I have to congratulate you for being about the only tool on the marked able to understand CR3 EXIF.

I use the CLI to create a file (on a RAM-disk) and then I use my own program to read the info I want from my photos. I also writes EXIF info - primarily GPS information - to the photos.
Having bought a Canon R6 I have to update my own program as well. A programmers life is never doll ;-)

I use the dates (creation time and date digitized/ date originated) to rename my protos (prefixing yyyymmdd-hh_mm_ss). Dates comes in many variations in these files it seams. Not really a problem if they informed the same time but alas they do not.
syntax could be "yyyy:mm:dd hh:mm:ss" or like "yyyy:mm:dd hh:mm:ss+01:00" (+ or - offset in hh:mm format).
I live in Denmark whitch is CET = UTC+1 (currently - until DST starts).

Today I made a shot of my wrist watch showing 09:49:08. Time on camera is set to about the same (it is like 13 seconds ahead so it must have been like 9:49:21 then), time zone Paris and DST off.
I then moved the photo to my windows 10 pro, 64 bit.

This is the dates showing in the resulting file using: exiftool.exe -a -u -g1 inputfile.CR3 > outputfile.txt
---- System ----
File Modification Date/Time     : 2021:03:03 08:49:21+00:00
File Access Date/Time           : 2021:03:03 08:58:56+00:00
File Creation Date/Time         : 2021:03:03 08:49:20+00:00
---- QuickTime ----
Create Date                     : 2021:03:03 08:49:20+00:00
Modify Date                     : 2021:03:03 08:49:20+00:00
---- Canon ----
Time Zone                       : +01:00
Time Zone City                  : Paris
Daylight Savings                : Off
---- IFD0 ----
Modify Date                     : 2021:03:03 09:49:20
---- ExifIFD ----
Date/Time Original              : 2021:03:03 09:49:20
Create Date                     : 2021:03:03 09:49:20
Offset Time                     : +01:00
Offset Time Original            : +01:00
Offset Time Digitized           : +01:00
---- Track1 ----
Track Create Date               : 2021:03:03 08:49:20+00:00
Track Modify Date               : 2021:03:03 08:49:20+00:00
Media Create Date               : 2021:03:03 08:49:20+00:00
Media Modify Date               : 2021:03:03 08:49:20+00:00
Media Time Scale                : 1
---- Track2 ----
Track Create Date               : 2021:03:03 08:49:20+00:00
Track Modify Date               : 2021:03:03 08:49:20+00:00
Media Create Date               : 2021:03:03 08:49:20+00:00
Media Modify Date               : 2021:03:03 08:49:20+00:00
Media Time Scale                : 1
---- Track3 ----
Track Create Date               : 2021:03:03 08:49:20+00:00
Track Modify Date               : 2021:03:03 08:49:20+00:00
Media Create Date               : 2021:03:03 08:49:20+00:00
Media Modify Date               : 2021:03:03 08:49:20+00:00
Media Time Scale                : 1
---- Track4 ----
Track Create Date               : 2021:03:03 08:49:20+00:00
Track Modify Date               : 2021:03:03 08:49:20+00:00
Media Create Date               : 2021:03:03 08:49:20+00:00
Media Modify Date               : 2021:03:03 08:49:20+00:00
Media Time Scale                : 1
Time Stamp                      : 2021:03:03 09:49:20.49
---- Composite ----
Create Date                     : 2021:03:03 09:49:20.49+01:00
Date/Time Original              : 2021:03:03 09:49:20.49+01:00
Modify Date                     : 2021:03:03 09:49:20.49+01:00
----------------------------------------------------------------------------------------------------------

So no shortage of timestamps ;-)

My problem is that my program will read EXIF from all of my approx 350.000 photos in order to rename files and import data into my own DB. I have had a few cameras (including smartphones) over the years. I am not sure what sections to expect from various brands and models. I hence plan to use them all if they are present - but end up having only 3 (created, digitized and modifyed).

Which fields should I put my money on?

:-) Freddy

[Phil Harvey]

Hi Freddy,

You should set the time zone of your computer properly.

CreateDate is probably the best overall date/time tag to use.  However, for videos there is a time zone complication.

- Phil

[FreddyFremad]

Time zone on my computer is set automatically and is correct: UTC+1 (Brussels, Copenhagen, Madrid, Paris =  CET).

Thank you - and I do not look at videos :-)

[Phil Harvey]

Time zone on my computer is set automatically and is correct: UTC+1 (Brussels, Copenhagen, Madrid, Paris =  CET).

Then I don't understand why the time zone is +00:00 in your output:

---- QuickTime ----
Create Date                     : 2021:03:03 08:49:20+00:00

The QuickTime CreateDate is displayed using the local system time zone.  Perhaps the time zone for the Windows command line is different? (I wouldn't be surprised.)  I found this description of how to change the Windows command-line time zone.

- Phil

[StarGeek]

Thank you - and I do not look at videos :-)

CR3 files use the same standard as MP4/Mov videos.  That's why you see Track1, Track2, etc in the output.

[Phil Harvey]

@StarGeek:  True.  But unlike videos, CR3 files always use UTC times, which is an important distinction here.  (ie. The QuickTimeUTC option is automatically enabled for CR3 files.)

- Phil

[FreddyFremad]

Hi,

I did not know timezones could differ on the same computer. You learn every day.

It was however not the case on mine:
C:\>tzutil /g
Romance Standard Time

I have also never heard of Romance Standard Time, but with the help from google I found that it is CET (Central European Time).

:-) Freddy

[Phil Harvey]

Then I don't understand why the time zone is +00:00 in your output:

- Phil