Feed Zippering

A “zippered” feed retrieves multiple RSS feeds and combines them into a single feed, with all items sorted by the publish date.

With no native method of sorting dates in XSL, I had to create a custom script to convert time-zones, and change the date into a usable numeric format for sorting. Support was needed for several different date formats. This was reusable code, and is routinely used for various news sites.