I keep all audio blogs published so far, so the lesson should be still on the site : )
Could you check if this lesson is what you are looking for, by the way?
By the way, we've made the new video series in the advanced level, which you can learn about Japanese Holidays in Japanese. Here's the link to the series. http://www.japanesepod101.com/index.php?cat=74 We'll also consider of having more audio contents in the advanced level.