Linting and housekeeping so I can read this without my editor going nuts.

Notes:
 - I've plonked in CDN versions of the scripts/stylesheets in at the top - this is mainly a convience for me as you don't have your entire tree committed. Also note that you were loading bootstrap.js twice, once as a script and once as a stylesheet...
 - Outside of script tags you are in HTML land, so long quotes need to be top and tailed with <!-- --> rather than // or /* */
 - Technically, everything should be within the HTML tag, and general practice dictates to keep script blocks inside the BODY. Generally we do this at the end so that it comes into being once everything is loaded.
Move event handles into respective views.

- Generally speaking, we don't want events to be sitting in general document scope, rather in the views which they affect. There is still some work to do interms of clearing up and unbinding events when we destroy the views, but for the most part and at this stage, this should work fine.
Refactor selection/activity view.

- It is generally better to send models to templates and let them do the grunt work rather than doing manual DOM manipulation in the render() function. This is one way through the problem, though it changes the intention of some of your views. Your choice here is going to be whether is is easier to have your data some down the wire already sorted in this kind of {day:[activity],...} pattern (e.g. do the grouping of database data server-side, or do it on the client.