calculating number of days between dates
<p>I'm aware of calculating number of days between two dates.   </p>

<p> <a href="http://stackoverflow.com/questions/7103064/calculate-the-number-of-days-between-two-dates">Calculate the number of days between two dates</a> </p>

<p>But i'm not able to understand how the calculation is made in below piece of code. Particularly the one which is highlighted below.</p>

<p><code>return (int)( (d2.getTime() - d1.getTime()) / (</code><strong>1000</strong><code>*</code><strong>60</strong><code>*</code><strong>60</strong><code>*</code><strong>24</strong><code>));</code></p>

<p>Kindly let me know the logic behind this.</p>
