Changing dates on mp4 metadata

Question

I've been trying to change the metadata dates in mp4 files using exiftool. I can only get it to change the "Date" (whatever that is) and "Media created" fields as displayed in Windows file explorer. However, I organise my pics and videos using Photoshop Elements and this appears only to read only the "Date Created" and "Date Modified" fields. These fields seem to resist all my attempts to modify them using the "exiftool "-modifydate

OK so it's 20 hours later. Thanks everyone for your helpful replies. It seems that Photoshop reads the system dates (Date, amended date, created date) and now I understand why exiftool won't write to these. Instead I found a free tool - Bulk File Changer - which amongst other things allows you to change Created Modified and Access dates with an option to read the required date from the individual file names, which is exactly what I want since all my file namesstart with the date and time of original creation! I haven't worked out the UTC thing but since I live in the UK, time is never far from UTC - close enough for cataloguing family pics and videos.

Answer 1

This is a combination of exiftool FAQs #2 & #3. You are trying to write "Date" but that isn't the actual name of the tag that Windows reads. Additionally, Photoshop Elements may be reading yet a different tag. And to add on to all that, I believe that Windows and Photoshop Elements will read the time stamps differently.

To look at all the timestamps for the file, run this command:
exiftool -time:all -G1 -a -s File.mp4
That will give you the actual tag names instead of tag descriptions. It will also show duplicate tags and what groups they belong to.

I believe the three tags you mostly likely want to try to alter are the FileModifyDate, FileCreateDate (both System tags, meaning they're a part of the underlying file system) and the Quicktime:CreateDate tags. To change these you would use this command:
exiftool -FileCreateDate="2019:07:22 12:00:00" -FileModifyDate="2019:07:22 12:00:00" -Quicktime:CreateDate="2019:07:22 12:00:00" FILE.mp4

Here's is where you run in to the second problem. According to the spec, the Quicktime:CreateDate tag is supposed to be in UTC. Windows understands this and displays the time correctly adjusted to the local time zone. From what I understand, Adobe programs do not read it properly and assume that the time is local time, not UTC. So if the timestamp is written according to the spec, Photoshop Elements will probably not show the proper time.

The above command will write the Quicktime:CreateDate value exactly as written. If you want to write the value according to the spec (adjusted to UTC), you can add -api QuickTimeUTC to the command and exiftool will adjust the time to UTC based upon the local computer's time setting, or if you include the time zone in the value written, e.g. -Quicktime:CreateDate="2019:07:22 12:00:00-05:00", then exiftool will use that to adjust to UTC. In that example, exiftool will end up setting the time to 2019:07:22 17:00:00. Windows will then read it as 2019:07:22 12:00:00 (assuming your time zone is EDT, -05:00) and Photoshop Elements will read it as 2019:07:22 17:00:00.

Answer 2

Here are three programs that have a bit overlapping features, and they all work a bit differently.

I used them to adjust the file creation date of Whatsapp image and video files on my phone.

I made a backup to the SD card (I did the backup on the phone), and when I restored the images on a new phone, the phone changed the file creation dates to the same current date and time to all the images. Then of course, everything appeared in the Gallery apps on the wrong dates and times.

So in the end I copied all the files to my desktop, adjusted the file dates (unfortunately not the times), and copied them back to the phone.

Bulk File Changer https://www.nirsoft.net/utils/bulk_file_changer.html

I used the creation date in the image and video file to change the file accessed date, and to change the other fields.

Exif Date Changer, but it only works for image files, not mp4. https://www.relliksoftware.com/exifdatechanger/#download

Advanced File Renamer was useful for mp4, when the files had no metadata at all, just the filename, to use the date in the file name, and modify the created, modified, accessed date. https://www.advancedrenamer.com/

Answer 3

FWIW created/modified date is usually Windows attributed and refers to the date a file was created or modified.

Whereas date for mp3/4 metadata refers to the date the song/album was recorded. You should be able to change the mp4 "date" metadata in Windows Explorer.

Method 1: - Highlight the song in WE. - Edit the metadata field(s) at the bottom of the screen. - Click Save.

Method 2: - Right-click the song in WE. - Select "Properties". - Select "Details". - Edit the metadata field(s). (N.B. To select the field, click to the right of field name) - Click Apply.

Answer 4

You can also try to use MP4Workshop. It is designed to edit the internal metadata of the MP4 file, and can also add timezone offset to make it align correctly with all other movies and pictures in for example GooglePhotos. It is free software, you can download from mp4workshop.com. It can handle single files, but also batches of files (including JPG and MOV). Greetings, John