I get that we have only a limited amount of space in the topic list, so I guess showing “Apr 2014” is not an option. But wouldn’t it be enough to just show “Apr” if it was posted in April this year and “Apr '14” if it was posted in April last year?
But we have enough space (even on mobile) when the actual posts are shown. So, I guess we could show the unabbreviated year (if needed) for posts.