Sometimes it will pass through the timestamp, not 'x days ago'
Here's some dates that give it trouble:
Sun Nov 17 2013 09:29:16 GMT-0800 (PST)
Sun Nov 17 2013 11:01:24 GMT-0800 (PST)
Sun Nov 17 2013 03:36:59 GMT-0800 (PST)
Not sure what the pattern is but I'm seeing it in maybe 10% of my dates