title: How do you convert a timestamp format within Javascript?
body: <p>how do I convert something like<br />
  <code>2020-12-01T15%3A48%3A39.862Z</code><br />
  to a timestamp format of<br />
  <code>2018-09-15T15%3A53%3A00-07%3A00</code>?</p>
  <p>I am not very familiar with timestamp formats and manipulation of datetime in Javascript...</p>