title: How to add missing data entries in an array between a given start date and end date
body: <p>I have an array named <code>plot_data</code>. In that I have two object properties date <code>x</code> and value <code>y</code>. The dates are actually past dates. In that array a few dates are missing somewhere at multiple places. So, whatever dates are missed I want to add them in the array.</p>
  
  <p>plot_data array is like this</p>
  
  <pre><code>0: {x: Fri Apr 06 2018 22:30:00 GMT-0500 (Central Daylight Time), y: 93.9}
  1: {x: Sat Apr 07 2018 09:00:00 GMT-0500 (Central Daylight Time), y: 69.3}
  2: {x: Tue Apr 10 2018 10:00:00 GMT-0500 (Central Daylight Time), y: 71.2}
  3: {x: Wed Apr 11 2018 11:00:00 GMT-0500 (Central Daylight Time), y: 67.2}
  4: {x: Sat Apr 14 2018 10:00:00 GMT-0500 (Central Daylight Time), y: 71.2}
  5: {x: Sun Apr 15 2018 11:00:00 GMT-0500 (Central Daylight Time), y: 67.2}
  </code></pre>
  
  <p>I want the output of the array like this.</p>
  
  <pre><code>0: {x: Fri Apr 06 2018 22:30:00 GMT-0500 (Central Daylight Time), y: 93.9}
  1: {x: Sat Apr 07 2018 09:00:00 GMT-0500 (Central Daylight Time), y: 69.3}
  2: {x: Sun Apr 08 2018 09:00:00 GMT-0500 (Central Daylight Time), y: null}
  3: {x: Mon Apr 09 2018 09:00:00 GMT-0500 (Central Daylight Time), y: null}
  4: {x: Tue Jun 10 2018 10:00:00 GMT-0500 (Central Daylight Time), y: 71.2}
  5: {x: Wed Jun 11 2018 11:00:00 GMT-0500 (Central Daylight Time), y: 67.2}
  6: {x: Thu Jun 12 2018 10:00:00 GMT-0500 (Central Daylight Time), y: null}
  7: {x: Fri Jun 13 2018 11:00:00 GMT-0500 (Central Daylight Time), y: null}
  8: {x: Sat Jun 14 2018 10:00:00 GMT-0500 (Central Daylight Time), y: 71.2}
  9: {x: Sun Jun 15 2018 11:00:00 GMT-0500 (Central Daylight Time), y: 67.2}
  </code></pre>
  
  <p>I am not getting idea how to do this, since we have to consider number of dates in a month. Please help.</p>