title: How to subtract this time in excel
body: <p>I have two timestamps (please see below) of format hh:mm:ss.000. I need to find out the time difference between two timestamps including milliseconds. Pleas help.</p>
  <p>column1   (20:47:39.891)      column2 (20:47:39.755)</p>
  <p>I have 10000 columns this way.</p>