How to determine epoch time range from today to past date, then determine equal amount of past time?
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<ul>
<li><p>So I know what today is: <strong>Thu 14 Jul =</strong> <code>1468523547</code></p></li>
<li><p>And I have an <code>alert</code> value for 1 week ago: <strong>Thu 07 Jul</strong> = <code>1467918688</code></p></li>
<li><p>Now I need my <code>start_epoch</code> (2weeks ago) that would equal the time between <strong>today</strong> and my <code>alert</code>. So that I can center my graph.</p></li>
</ul>

<p>In my case above, I need to determine 1 week ago from the <code>alert</code>.</p>

<p><em>Timespans could be a week and a half ago, 6 days etc etc</em></p>

<p>Is there an easy way to accomplish this using <a href="http://momentjs.com/" rel="nofollow noreferrer">momentjs</a>?</p>