I'd prefer actual dates over relative dates.
I'd prefer seeing dates as July 7, 2012 15:45 in addition to or in replace of "2 weeks ago"
Jonathan Julian commented
Many people like the ease of reading relative dates. A great way to appease both crowds is to place the full UTC timestamp in a tooltip when hovering over the relative date text.
Totally agree, "yesterday" is totally useless when we try to know if the error happened before or after the commit I did yesterday...