I like how you also did that with the dates (e.g. "Friday" goes to "Fri")
Unsolicited feedback: At the narrower widths, the sidebar (.secondary) would be better off falling after the main content (.primary) It might also work having "Filter by topic" turned into a drop down.
I did a php app for a client on Media Temple's (gs) and it was unbearably slow. The php execution time would vary drastically (.1 seconds to over a minute) even on a simple debugging page. After a lot of back and forth with customer service and never being able to pinpoint the issue, I switch to Linode.
Maybe things will change with how the browser implements fractions but 112/3 = 11(2/3) and 3431/5147 = 3431/5147 (there is no 1/5) http://imgur.com/a/4FFNy
My algorithm, given a strip, would tell you which strip was on the right and also gave a certainty. The last strip would have a "next strip" value shared with an earlier strip (thus wrongly attached) but with less certainty.
Edit: Or (worst case) the last strip would have a high degree of uncertainty.
