title: Incrementing Timestamps
body: <p>I have a Python script converting multiple csv lists into one xml document with time stamps for each row
  I already have the format set as:</p>
  
  <pre><code>TS = datetime.now().isoformat(timespec='milliseconds')+ "Z"
  </code></pre>
  
  <p>calling TS will give me this time stamp = <code>2020-02-14T14:30:59.237Z</code></p>
  
  <p>I need to reuse this variable possibly 100k times or more in my XML document and this creates the exact same time, every time I call the variable. How can I increment the time stamp by 1 millisecond every time it is called in the script??</p>