Specify datetime format and expand dates and items to include descriptions

This should address the remaining issues on #2 

I'm not tied to ISO8601 as the date/time format. I just know of 2 date/time standards:

1. Seconds since UNIX Epoch (Jan 1st 1970) - ``1373134826``
    Pros: It's a nice simple integer and supported universally.
    Cons: It's an opaque number and provides no timezone information.

2. ISO8601 - ``2012-01-30T05:06:07Z``
    Pros: It's human readable and has a well defined standard. Supports timezones.
    Cons: Ugh, timezones. Also there are some ambiguities like "T" or " " as the separator.