When viewing a user profile for a mostly inactive user (For example, akmad), the activity displayed goes back multiple years, but there is no year value for "ancient" activities and it does not make sense.....
Note how in the above picture, it appears the sort-order is wrong because the Jan 12 stuff happens after the Jan 19 stuff (and the Jan 19 stuff actually happens in different years - making it look like the user got Yearling badge twice in a year?). Also, the Dec 17 stuff appears to happen after the Dec 24 stuff).
To be consistent with other date values in Code Review Stack Exchange, the dates older than a year should have the actual year value displayed, so the Dec 17 date should be unchanged, but the Dec 24 date should include the year 2015, etc.