This post processor would recognise dates in English text.
It should output an ISO-8601 dates [1] (initially
simply <span title="{ISO-8601 date here}"> would be a
good start).
These ISO-8601 dates could then allow the forum to e.g.
automatically convert them to the user’s time zone, or
add a link to add them as a calendar event, take them
in the filtering process, etc.
~Grauw