How to make release date and copyright metadata display on iPhone

Hello, I am new to using mp3tag and would appreciate some help formatting metadata. When viewing albums in my iPhone, I would like to be able to incorporate exact release dates (not just the release year) and copyright in the display of albums that I've added to my library manually. However, all my attempts so far have been unfruitful.

Attached are two screenshots from my phone, the first a single I added manually showing the issue, and the second a single downloaded from Apple Music exemplifying how I would like it to look.

I have already messed around with mp3tag a bit and figured out how to add explicit tags to manually added songs (as shown in the first screenshot), but I cannot figure out the release date and copyright metadata. The next attachment shows my progress so far in mp3tag, attempting to work with the "ITUNESPURCHASEDATE", "Year", and "Copyright" tags (The value "ye" is just a placeholder for now to see if it works).

My phone is an iPhone 13 running on iOS 15.6.1. The iTunes application on my PC has been updated to version 12.12.5.8. My mp3tag app is version 3.17. Files that I've been adding manually, I've been converting to AAC/MP4 files, since I read that only these files can be made to have the explicit tag.

I've run across a few threads on here discussing this, but they're mostly old, so I'm guessing that's why nothing has worked so far. Any help would be greatly appreciated.

These are not really standard metadata fields. They are xml data written into a custom iTunes comment field.

COPYRIGHT gives you the copyright text, and YEAR will have to be formatted YYYY-MM-DD

Is there a metadata field that I am missing to make this work? I have read other threads where users have claimed that they've solved the issue, with the end result being that the full release date is written out, formatted as "[name of month written out] [day of month], [year]". But none of their methods have worked for me.

I've tried formatting the YEAR field as YYYY-MM-DD, but it has not worked. Some have said it needs to be formatted "YYYY-MM-DD" + the letter "T" + "HH:MM:SS" + the letter "Z", but that also has not worked for me.

The field YEAR has always only 4 digits.
A field with the mentioned longer format would be RELEASETIME.

A quick check of a file that does show this will help. Open the Enhanced Tag viewer and look for the info you see there. [Edit - this info applies when editing video details for iTunes: You will notice that there are a couple of fields that are not standard, and have long hex values displayed. This is where Apple has buried this info. Perhaps you can dissect it from there, but I haven’t spent the time myself to do that.]

It is how I described it. But remember that you can’t just change the metadata and it will be synced to the iPhone. You have to remove the file, sync and then upload it. As is mentioned the Music app stores the data on device as an xml file and will not automatically trigger load of the metadata from the actual file.

the second screenshot shows
(p) 1972 Warner Records Inc.
which is not the same as (c) copyright.

See eg.g here:

For Apple Music and iTunes it is the Copyright field, it is up to the record label to decide if they add only ℗ (phonogram copyright) or/also © (copyright for the work outside of the recording itself).

Sorry, I have to admit that I didn't clarify in my previous post that this is not possible to do with mp3 files. And the info about the xml data is specifically for video files in iTunes. I've edited that earlier post now to avoid confusion. Apologies for misguiding anyone.

As @AreDigg correctly has indicated, you can add the COPYRIGHT and YEAR information to m4a files to get those details. To get the date information to show this way, you will need to use the standard full date and time format like this example 1996-06-26T12:00:00Z in the YEAR field.

I have tried formatting the RELEASETIME, YEAR, and COPYRIGHT fields in the multiple ways suggested in this thread so far. And with each attempt I've deleted the song from iTunes and re-added it to hopefully enact the changes made in mp3tag. Still nothing unfortunately. Still displays the same way as in the first screenshot.

If you have a file that shows the way you want it and one that does not - have you compared the fields in the extended tags dialogue Alt-T to see which fields differ from each other?