title: Given a table with events happening on a specific time; how do I divide the time into frequencies and count them
body: <p>I've been given a table with card accidents and at which time they occurred (Format HH:MM).</p>
  <p>I want to create a new column in the DF where the time is an interval of 15 minutes (ex. 10:30 - 10:45).</p>
  <p>With that information, I want to create a count plot that counts the number of accidents for each time interval.</p>
  <p>How can I do this?</p>