I have a website with a number of long form content articles that I keep updated. The page generates two date snippets from this:
<time itemprop="datePublished" datetime="2014-04-29T14:08:40+01:00">Published: 29 Apr 14</time>
<time itemprop="dateModified" datetime="2015-03-22T14:59:33+00:00">Last Updated: 22 Mar 15</time>
The date Google displays in the SERPS however is always the date published date.
Moz however has the last updated date for its beginners guide to SEO used in the SERPs.
It has the following two date snippets used:
<meta itemprop="datePublished" content="2014-03-04T17:42:15-05:00">
<div id="last-updated">01.08.2015</div>
Has anyone seen any patterns with on how Google decides which date to use?