Today, the first of May, is "May Day."
I didn't know, exactly, what this holiday commemorated--or even why it was on this date--until relatively recently.
According to several accounts I read, this date marked, on pagan calendars, the beginning of summer. On or around this date in the Northern Hemisphere, the Earth is halfway between the Spring Equinox and Summer Solstice. So why this would be considered the first day of summer--especially in the climates of some pagan lands--I don't know.
This date is also significant in the labor movement--again, for reasons I learned only recently. In some countries, particularly in Europe, it's celebrated in much the same way as Labor Day (the first Monday in September) here in the US. Ironically, the origins of the European holiday--which is called International Workers' Day or some translation thereof--started as a commemoration of the Haymarket Massacre in Chicago.
Another thing I learned only recently is the answer to this question: How did "May Day" become a call of distress? I thought it had its origins in how oppressed some workers were (and are); they would call "May Day" in much the same way others might cry "uncle" or call for their mothers. That may be the case, but it seems that it originated with Frederick Mockford, a senior radio officer at London's Croydon Airport. At that time--in the 1920's--air traffic over the English Channel was increasing, but still treacherous. Apparently, Mockford took the French pilots' distress call, "M'aider!"--which means "Help me!" and sounds like "May Day" to Anglophone ears--and popularized it.
Today sunshine refracted through clouds is glinting off pavement and trees as it does after a night of rain. The air is brisk, but not cold. I am going for a ride--and I hope I won't have to call "Mayday!"