I know there has been a number of posts for the way the date/time is displayed in Group View and in Forum View. I would like to add to this further.

If a topic/post was added today , I would like to see in the last poster section to display, “today, [the time]” i.e. today, 11:30.
If a topic/post was added yesterday, I would like to see in the last poster section to display, “yesterday, [the time]” i.e. yesterday, 16:21
If a topic/post was added 2 or more days ago, I would like to see in the last poster section to display, “[the date]” only, i.e. 20 Feb 2012.

It is a long shot but is this even possible? I have tried different combinations within the template but understand that it is probably the core files that need changing which I do not wish to attempt to modify.

Thank you in advance.