Repository: yt-dlp
Issue: m4a metadata create/modified dates for youtube downloaded audio streams recently became invalid
Labels: bug,external issue,core:post-processor

### DO NOT REMOVE OR SKIP THE ISSUE TEMPLATE

- [X] I understand that I will be **blocked** if I *intentionally* remove or skip any mandatory\* field

### Checklist

- [X] I'm reporting that yt-dlp is broken on a **supported** site
- [X] I've verified that I have **updated yt-dlp to nightly or master** ([update instructions](https://github.com/yt-dlp/yt-dlp#update-channels))
- [X] I've checked that all provided URLs are playable in a browser with the same IP and same login details
- [X] I've checked that all URLs and arguments with special characters are [properly quoted or escaped](https://github.com/yt-dlp/yt-dlp/wiki/FAQ#video-url-contains-an-ampersand--and-im-getting-some-strange-output-1-2839-or-v-is-not-recognized-as-an-internal-or-external-command)
- [X] I've searched [known issues](https://github.com/yt-dlp/yt-dlp/issues/3766) and the [bugtracker](https://github.com/yt-dlp/yt-dlp/issues?q=) for similar issues **including closed ones**. DO NOT post duplicates
- [X] I've read the [guidelines for opening an issue](https://github.com/yt-dlp/yt-dlp/blob/master/CONTRIBUTING.md#opening-an-issue)
- [ ] I've read about [sharing account credentials](https://github.com/yt-dlp/yt-dlp/blob/master/CONTRIBUTING.md#are-you-willing-to-share-account-details-if-needed) and I'm willing to share it if required

### Region

USA

### Provide a description that is worded well enough to be understood

1. Download a youtube audio stream (e.g. yt-dlp -vUf 599 78Ok52tMB30)
2. examine the timestamps in the m4a metadata using https://exiftool.org/
   Create Date                     : 0000:00:00 00:00:00
   Modify Date                     : 0000:00:00 00:00:00
   Track Create Date               : 0000:00:00 00:00:00
   Track Modify Date               : 0000:00:00 00:00:00
   Media Create Date               : 0000:00:00 00:00:00
   Media Modify Date               : 0000:00:00 00:00:00
3. older downloaded files show valid timestamps

They should either be valid or at least missing if valid ones can't be retrieved. Other software may rely on them. In the mean time, is there an option to force omit them from the m4a?


### Provide verbose output that clearly demonstrates the problem

- [X] Run **your** yt-dlp command with **-vU** flag added (`yt-dlp -vU <your command line>`)
- [ ] If using API, add `'verbose': True` to `YoutubeDL` params instead
- [X] Copy the WHOLE output (starting with `[debug] Command-line config`) and insert it below

### Complete Verbose Output

```shell
[debug] Command-line config: ['-vUf', '599', '78Ok52tMB30']
[debug] Encodings: locale cp1252, fs utf-8, pref cp1252, out utf-8, error utf-8, screen utf-8
[debug] yt-dlp version stable@2023.12.30 from yt-dlp/yt-dlp [f10589e34]
[debug] Lazy loading extractors is disabled
[debug] Python 3.12.1 (CPython AMD64 64bit) - Windows-10-10.0.19045-SP0 (OpenSSL 3.0.11 19 Sep 2023)
[debug] exe versions: ffmpeg 5.1.2-full_build-www.gyan.dev (setts), ffprobe 5.1.2-full_build-www.gyan.dev
[debug] Optional libraries: Cryptodome-3.20.0, brotli-1.1.0, certifi-2024.02.02, mutagen-1.47.0, requests-2.31.0, sqlite3-3.43.1, urllib3-2.2.0, websockets-12.0
[debug] Proxy map: {}
[debug] Request Handlers: urllib, requests, websockets
[debug] Loaded 1832 extractors
[debug] Fetching release info: https://api.github.com/repos/yt-dlp/yt-dlp/releases/latest
Latest version: stable@2023.12.30 from yt-dlp/yt-dlp
yt-dlp is up to date (stable@2023.12.30 from yt-dlp/yt-dlp)
[youtube] Extracting URL: 78Ok52tMB30
[youtube] 78Ok52tMB30: Downloading webpage
[youtube] 78Ok52tMB30: Downloading ios player API JSON
[youtube] 78Ok52tMB30: Downloading android player API JSON
[youtube] 78Ok52tMB30: Downloading m3u8 information
[debug] Sort order given by extractor: quality, res, fps, hdr:12, source, vcodec:vp9.2, channels, acodec, lang, proto
[debug] Formats sorted by: hasvid, ie_pref, quality, res, fps, hdr:12(7), source, vcodec:vp9.2(10), channels, acodec, lang, proto, size, br, asr, vext, aext, hasaud, id
[info] 78Ok52tMB30: Downloading 1 format(s): 599
[debug] Invoking http downloader on "<<EXCISED>>"
[debug] File locking is not supported. Proceeding without locking
[download] Destination: @CallMeKevin explores the wild world of simulation games [78Ok52tMB30].m4a
[download] 100% of 1002.64KiB in 00:00:00 at 6.59MiB/s
[FixupM4a] Correcting container of "@CallMeKevin explores the wild world of simulation games [78Ok52tMB30].m4a"
[debug] ffmpeg command line: ffmpeg -y -loglevel "repeat+info" -i "file:@CallMeKevin explores the wild world of simulation games [78Ok52tMB30].m4a" -map 0 -dn -ignore_unknown -c copy -f mp4 -movflags "+faststart" "file:@CallMeKevin explores the wild world of simulation games [78Ok52tMB30].temp.m4a"
```