title: float value after second position in time 04:55:49.9242 ( what is this .9242)
body: <p>Can anyone please explain me &quot;2018-04-17 04:55:49.9242&quot; what is the .9242 after :sec value.</p>
  <p>i am parsing some data from json. one of the file contains this value. i know the date format how is here. only have some doubt in .9242 part.</p>