Help changing "Media created" field in MTS and MPG files

[flyerii]

The "Media Created" field (Windows 10) for my many of .mpg, .mts, .wmv, and .3pg files are empty.  Is there a way to update these? 

I tried

exiftool -ext MTS "-CreateDate=2021:01:01 12:00:00" foo.MTS

but get the error message

Error: Writing of MTS files is not yet supported - foo.MTS

[StarGeek]

Is there a way to update these?

If you check the Supported File Types table, you'll see that there is only read support.

Phil has previously said that the format is "a nightmare" and write support is unlikely.

I'm sorry to say that I doubt ExifTool will ever have the ability to write these files.  See this commentary for a few reasons why this format is at the bottom of my list.