setting MKV date

[larryc]

Is there any way to (re)set the encoded date property in an mkv file?
I have a bunch of videos originally from my camera that have been encoded to MKV. I'd like to embed the date I took these videos directly in the file. Right now the date field contains the date I encoded them using mkvmerge.
I tried playing with mkvpropedit but could not figure out if or how to set the date property. Is this possible?

[zoobie]

sure...just change the calendar in your OS before encoding by double-clicking the clock in Windows
you also need to fill out your computer details for future questions

[larryc]

Resetting the system clock might work, but that's pretty inelegant. Although I use Windows now, the Unix hacker in me was trained long ago to never set the system clock backwards.

Not trying to be argumentative, but why do you need my system details to answer the question "Can I use mkvpropedit to change the date field in an mkv file?"

[Wolfen]

You could embed the date you made the videos with the mkvmerge header editor. Open the header editor under the file drop down, open your file and under segment information add element in title section and in new value put the title and the date of the file.

[larryc]

Wolfen, I'm kinda new at working with MKV files. Are you saying I should just write the date to the title field? Or is there a way I can add a date field to the segment information?

Ideally I'd like to set the date_recorded field per this page http://matroska.org/technical/specs/tagging/index.html but I am feeling stupid in that I can't seem to figure out how to use mkvpropedit to set it.

[guns1inger]

If you want to change the file date attributes you may need to use something like this : http://www.febooti.com/products/filetweak/ or use google to find other "file date changer"s (hint)

[zoobie]

the reason we ask you to fill out your system details for future questions is so we can see what setup you have at a glance and make suitable recommendations that otherwise may not be possible

[larryc]

@guns1inger, just to be clear, I am not trying to change the file's timestamp (that's easy); I'm trying to change the metadata or tag within the MKV file that denotes the creation date. File timestamps can change too easily which why I want to capture the recording date within the file itself. The febooti suggestion looked interesting, but it only seems to work with jpg (exif) metadata, not mkv metadata or tags.

[poisondeathray]

Maybe you could use a hex editor?

[nitewulf]

anyone ever figure out how to do this? I'm looking to do the same thing. I'm comfortable using a HEX editor, just don't know how to find the right bytes to edit.

[Selur]

doesn't https://forum.videohelp.com/threads/376220-mass-edit-mkv-encoded-date help?

[nitewulf]

Yes and no. I may end up use ffmpeg though I'd rather not rely on a 3rd party application. I'd like to learn how to edit the HEX myself. I'd like to know how that ffmpeg command alters the embedded timestamp. Perhaps the guys that made it will share.

[Selur]

I'd like to learn how to edit the HEX myself.

Fair enough, but where is the problem?
With a hex editor it's straight forward for me:

• start the hex editor (for example HxD)
• go to the end of the file and look for CREATION_TIMED (alternatively search for CREATION_TIMED)
• edit the date shortly behind that entry
• save file

-> nothing magic, no extended knowledge of the mkv structure or similar stuff required

[nitewulf]

Interesting. I've looked at half a dozen .mkvs that I have and have only found CREATION_TIMED in 2 of them. I've used a few different applications to encode them over the years. I wonder if they've used different file format standards.

[Selur]

Not all fields/flags are mandatory, lots are optional.

[nitewulf]

Yeah I'm seeing that. I'm finding more and more that I really don't like .mkv files. .mp4 is much better defined.

https://matroska.org/technical/specs/index.html

Is their specifications. I even asked then about it and was pointed back to the specification and told to look at the DateUTC element in the Segment section.... NONE of the .mkv files I have looked at have 44 61 (the HEX supposed to represent the start of that value) in that section. It is optional after all... The CREATION_TIMED you pointed out is not in their specification yet it is in several .mkvs i have looked at.

I've been trying to add the DateUTC element and the CREATION_TIMED to the Segment of some .mkvs that are missing it and have so far been unsuccessful. I'll try more after work.

[Selur]

.mp4 is much better defined.

not really

I've been trying to add the DateUTC element and the CREATION_TIMED to the Segment of some .mkvs that are missing it and have so far been unsuccessful.

Not surprised, the hex method only works if there is a CREATION_TIMED entry. You can't simple add something to a container without also making sure the rest of the structure accounts for it. (hashs&co)


To make sure what date do you want to change add? (what do you use to check that date?)
The thing is mkv allows nearly everything as custom tag and it's a question of which tool is reading the tags and interpreting them.
In example some applications interpret 'creation date' , 'encoded date' , 'created' all as one and simple display the first as 'Encoded date'.

[Jellybit]

I've found this thread as the first result every time I tried to figure out how to batch modify the date in a MKV header in the past year. I was surprised that no one seemed to address the original question, which is asking if mkvpropedit can modify the date in this header, and how it's done. To all those like me who find this thread again and again at the top of the Google results in the future, I just figured it out. Here's how it's done:

mkvpropedit video.mkv --edit info --set "date=1974-05-22T01:00:00+05:00"

What this does, is set the date to May 22nd, 1974. The time will be 1AM, and the time zone will be UTC+5:00. Here's more information on the date format:

The recognized format is 'YYYY-mm-ddTHH:MM:SS+zz:zz': the year, month, day, letter 'T', hours, minutes, seconds and the time zone's offset from UTC; example: 2017-03-28T17:28-02:00. The letter 'Z' can be used instead of the time zone's offset from UTC to indicate UTC aka Zulu time.

As mentioned above, the date can be stored in something other than "date", but this can edit it regardless. It's strange. Even the mkvpropedit batch GUIs seem to miss this property. While hex editing is a possibility, now I can create my own batch edits to many files at once. Sorry to resurrect this thread, but considering the prominent long-term Google result, I figure it's worth it.