title: How can I batch-modify timestamp metadata on MP4 video files
body: <p>I recently discovered that one of my cameras had its internal clock set almost two-years behind the actual date/time, which upset the ordering of photographs and videos in my library timeline. I quickly discovered the wonderful batch-update functionality of <code>exiftool</code>'s <a href="https://ExifTool.org/#shift" rel="nofollow noreferrer">date/time shift feature</a>. Unfortunately however it does not yet support modification of MP4 video files:</p>
  <pre><code>$ exiftool -AllDates+=&quot;0:0:729 3:17:0&quot; test.mp4
  Error: Writing of MP4 files is not yet supported - test.mp4
      0 image files updated
      1 files weren't updated due to errors
  </code></pre>
  <p>How can I perform similar batch-date-shifting functionality for MP4 video files?</p>