I added support for the Dublin Core (dc) and Media RSS (media) namespaces in feeds. My favorite part of this was handling date and time because it is always just so fun. In Dublin Core, not only do the specs say that you can have incomplete ISO-8601 timestamps like (2000), (2000-01) but you could also specify time ranges like (2000/2000-02-01) https://www.dublincore.org/specifications/dublin-core/dcmi-terms/#date meaning the publishing date is somewhere between 2000-01-01 and 2000-02-01 leading to this amazing function. The best part of all this is that there is going to be more complicated date time handling when I write the syndication (sy) namespace handler.