 <p>OK here is a jsFiddle with AN answer: <a href="http://jsfiddle.net/ccarns/2gMyx/" rel="nofollow">http://jsfiddle.net/ccarns/2gMyx/</a></p> <p>The reason I say that is I cheated a bit because every(2).months(); and other methods I tried for every two weeks would return unexpected results.</p> <pre><code>later.parse.recur().on(_dayOfTheMonth).dayOfMonth().every(2).month(); </code></pre> <p>For instance a start date of 12/1/2013 would return the same results as 1/1/2103 (both returning the first value as 1/1/2103). It seem like the implimenation treated every 2 as every odd month. Try the original fiddle at top to see what I mean.</p>