Sort RSS parser on Wordpress site by date order

I have a list of music gigs displayed on the front page of my site (built in Wordpress), that is collated using an RSS feed from Reverbnation. It does not appear in date order - it may be the scripts fault, or it may be the fault of the original RSS feed. Either way, I need the list shown in date order.

Scrrenshot of the problem (see bottom of the list): http://i.imgur.com/hxMNbCZ.png
The code currently used: http://pastebin.com/xy3TseEc