Escaping characters in entry.postDate|date {{ entry.postDate|date('jS F Y \at ga') }}This should produce this 5th November 2016 at 4ambut it doesn't seem to recognise the escape and adds 30 instead of at.
You'll actually need to add a double backwards slash in front of each character you want to escape, i.e.

{{ entry.postDate|date('jS F Y \\a\\t ga') }}


See the official Twig docs for more info.