They&#x27;re both in February. Months represented by integers start at 0.<p><pre><code>    &gt; new Date(2016,1,11)
    Thu Feb 11 2016 00:00:00 GMT-0800 (PST)
    &gt; new Date(&#x27;2016-02-11&#x27;)
    Wed Feb 10 2016 16:00:00 GMT-0800 (PST)
</code></pre>
I make the same mistake constantly even though I learned this years ago.