Happy leap-day to anyone reading this! How often does a leap-year occur? It is not once every 4 years anymore. It is more like 97 times every 400 years! Adding a day once every 4 years would be correct if the year was 365.25 days long. This is what the Julian calendar did. But then it was discovered that a year is more like 365.2425 days which led to the Gregorian calendar. I like the story of how this was implemented. Centuries of not accounting for this difference caused a 10 day discrepancy between the night sky of 4 October 1582 and the night sky of 4 October in the year that the Julian calendar started. Therefore Pope Gregory XII pronounced that the next day would be 15 October 1582 making the month have 21 days.
The system now is to add an extra day to years that are divisible by 400 and to years that are divisible by 4 but not 100. This means that while the year 2000 was a leap-year, the year 2100 will not be. My prediction is that at least a few printed calendars will be incorrect in the year 2100.
Anyway, what I actually want to talk about is a series of Pronunciation Manual videos on YouTube. The channel parodies instructional language videos by telling you the worst possible way to pronounce something. The meme started in April 2011, I think as a way to take advantage of video monetization. It is stupid simple to make a PronunciationManual video. Each one is 8 seconds long and just consists of a printed word with a voice over.