More than one date for Google Photos

More than one date is associated with each photo file:

in metadata —
1. [EXIF:IFD0] ModifyDate
2. [EXIF:ExifIFD] DateTimeOriginal
3. [EXIF:ExifIFD] CreateDate

on Microsoft Windows —
4. [File:System] FileModifyDate
5. [File:System] FileAccessDate
6. [File:System] FileCreateDate

on Linux —
4. [File:System] FileModifyDate
5. [File:System] FileAccessDate
6. [File:System] FileInodeChangeDate

and more in metadata —
7. [IPTC] DateCreated
8. [IPTC] TimeCreated
9. [EXIF:ExifIFD] SubSecTimeOriginal
10. [EXIF:ExifIFD] SubSecTimeDigitized
11. [EXIF:GPS] GPSTimeStamp
12. [EXIF:GPS] GPSDateStamp
13. [XMP:XMP-xmp] CreateDate
14. …

:and file system dates may change when a file is copied or moved between computers. So it isn't too surprising when computer programs show different dates for a photo.

In particular, note that [File:System] FileCreateDate is available on Microsoft Windows but not available on Linux — so perhaps FileCreateDate is simply not available to Google Photos. When Google Photos does not show the date we expect, we need to make more data available before we upload.

These details are for Microsoft Windows, the details will be slightly different for other computers.

The Tools:

1. Command Prompt aka Terminal
2. ExifTool — download this amazingly wonderful photo software

The Steps:

1. Check which dates are associated with a photo file
2. Check which date Google Photos will choose
3. Add CreateDate to metadata
4. Add DateTimeOriginal to metadata
5. Upload the photo files to Google Photos

The Steps in laborious detail:

1. Check which dates are associated with a photo file

• Open a command prompt.
• Change directory at the command prompt to a folder of photo files uploaded to Google Photos.
• Choose one of those photo files that Google Photos does not show with the date you expect.
• Use the following exiftool command, at the command prompt, to look at the dates associated with a.jpg —

  exiftool -s -a -G0:1 -time:all a.jpg

  [File:System]   FileModifyDate   : 2018:03:15 09:51:34-07:00
  [File:System]   FileAccessDate   : 2018:03:15 09:53:46-07:00
  [File:System]   FileCreateDate   : 2018:03:15 09:57:15-07:00
  

• Does one of the dates and times, associated with a.jpg, match the date and time shown by Google Photos?

2. Check which date Google Photos will choose

1. DateTimeOriginal — if available; if not then:
2. CreateDate — if available; if not then:
3. ModifyDate — if available; if not then:
4. FileModifyDate

For a.jpg Google Photos would choose the FileModifyDate — because that's what was available.

3. Add CreateDate to metadata

We can make CreateDate available to Google Photos by copying the current FileCreateDate to Exif metadata:

• Open a command prompt.
• Change directory at the command prompt to your working folder.
• Use the following exiftool command, at the command prompt, to look at the dates associated with all the photo files in the current folder —

  exiftool -s -a -G0:1 -time:all . 

  ======== ./a.jpg
  [File:System]   FileModifyDate   : 2018:03:15 09:51:34-07:00
  [File:System]   FileAccessDate   : 2018:03:15 09:53:46-07:00
  [File:System]   FileCreateDate   : 2018:03:15 09:57:15-07:00
  ======== ./b.jpg
  [File:System]   FileModifyDate   : 2018:03:15 09:52:46-07:00
  [File:System]   FileAccessDate   : 2018:03:15 09:52:46-07:00
  [File:System]   FileCreateDate   : 2018:03:15 09:57:15-07:00
      1 directories scanned
      2 image files read
  

• Use the following exiftool command, at the command prompt, to copy the current FileCreateDate to Exif metadata - for all the photo files in the current folder —

  exiftool -P "-CreateDate<FileCreateDate" -if "not $CreateDate" . 
      1 directories scanned
      2 image files updated
  
  

  exiftool -s -a -G0:1 -time:all .
  ======== ./a.jpg
  [File:System]   FileModifyDate   : 2018:03:15 09:51:34-07:00
  [File:System]   FileAccessDate   : 2018:03:15 09:53:46-07:00
  [File:System]   FileCreateDate   : 2018:03:15 09:57:15-07:00
  [EXIF:ExifIFD]  CreateDate       : 2018:03:15 09:57:15
  ======== ./b.jpg
  [File:System]   FileModifyDate   : 2018:03:15 09:52:46-07:00
  [File:System]   FileAccessDate   : 2018:03:15 09:52:46-07:00
  [File:System]   FileCreateDate   : 2018:03:15 09:57:15-07:00
  [EXIF:ExifIFD]  CreateDate       : 2018:03:15 09:57:15
      1 directories scanned
      2 image files read
  

• Use the following exiftool command to not make backup files, and to process all subfolders of the current folder as-well-as the current folder —

  exiftool -overwrite_original -r -P "-CreateDate<FileCreateDate" -if "not CreateDate" . 
  

• Note: only photo files without a CreateDate in Exif metadata will be updated —

  exiftool -P "-CreateDate<FileCreateDate" -if "not CreateDate" . 
      1 directories scanned
      2 files failed condition
      0 image files read
  

4. Add DateTimeOriginal to metadata

We can make DateTimeOriginal available to Google Photos, if it's missing.

Digital photos record the date and time when a photo was taken; scanned photos don't. So for scanned photos DateTimeOriginal is probably missing.

• Here's a separate step-by-step explanation of how to add the dates we think the original photos were taken.

5. Upload the photo files to Google Photos

• If the photo files had been uploaded before making these changes, then it may be better to delete them from Google Photos before uploading these changed files: to avoid duplicates.
• Upload the photo files to Google Photos
• Delete the working copies of the photo files from your working folder

Summary:

Although many dates may be associated with a photo file; when a photo is uploaded to Google Photos, just one of those dates will be chosen and shown for that photo. Before upload, we can decide which date we want Google Photos to choose and make that date available in the photo file metadata.