 <p>As @CBroe points out, this isn't supported by the Facebook Graph API. (It can be done using <a href="https://developers.facebook.com/docs/reference/fql/" rel="nofollow">FQL</a>, but that's deprecated and won't be supported for much longer).</p> <p>That said, with some creativity (and a bit extra code) a similar effect can be achieved by combining a couple of queries. </p> <p>In my application, I perform a query with the following parameters:</p> <ul> <li><code>until=2015-07-07</code> (or whatever the <code>since</code> date would have been)</li> <li><code>fields=updated_time</code> (to keep the query fast and the payload small)</li> <li><code>limit=5000</code> (or some similarly large page size, as I'm only grabbing one field)</li> </ul> <p>I then evaluate each post that has an <code>updated_time</code> greater than the would-be <code>since</code> date, and throw those posts into a queue to download the entirety of the post content. </p> <blockquote> <p><em>Note:</em> If you're dealing with content where there are frequent updates on past content, you'd likely want to use the Graph API's <a href="https://developers.facebook.com/docs/graph-api/making-multiple-requests" rel="nofollow">Batch Requests feature</a>, as opposed to downloading each post individually.</p> </blockquote> <p>So, for example, if the <code>until</code> (and, thus, <code>since</code>) date is <code>2015-07-07</code> and the <code>updated_time</code> on a post is <code>2015-10-15</code>, then I know that post was created prior to <code>2015-07-07</code> but updated afterwards. It won't get picked up in a <code>since</code> query, but I can easily download it individually to synchronize my cache.</p>