I am using HTML
<time class="meta" datetime="DD/MM/YYYY">13/07/2016 00:00:00</time>
I think there is some confusion regarding tag.
According to MDN:
This element is intended to be used presenting dates and times in a machine readable format. This can be helpful for user agents to offer any event scheduling for user's calendar.
In your code,
<time class="meta" datetime="DD/MM/YYYY">13/07/2016 00:00:00</time>, the output will not change by format you specify by datetime attribute, because it is meant for machine reading, but the text part of this tag that is 13/07/2016 00:00:00 will be visible on page to humans.