Kristen Lippincott

Well, yes and no.

It is arbitrary in that May is just a name for a group of days put together.

But the idea of May and the idea of having a seasonal calendar goes way, way, way back to prehistoric times.

So what were these prehistoric calendars like?

The first reason why you would have a calendar is basically for survival.

It would be tracking the changes in environment, in climate.

For example, you'd want to know when the rains were coming, when it would be hot, when it would be cold, animal migration, sailing in the Mediterranean, things like that.

people very quickly realized that they could tie these, what we would now call annual events, to the positions of the stars in the skies.

So, for example, the annual flooding of the Nile came with the morning rising of Sirius, or Hesiod says, don't sail when the Pleiades have set.

So it's kind of how you can set markers in order to keep your community surviving.

Well, the first written calendars are usually things like tracking the phases of the moon.

There are scratchings on old bones that we now think are probably rudimentary calendars.

If you think about yourself sitting in a field for a year...

the first thing you will notice is how the moon changes every night.

And that's why most of the very early calendars are lunar.

And then later you get the solar calendar when they say, oh yeah, we've come full circle again and the sun's in the same place as it was in the sky, this time 365 days.

So if you look, for example, some civilizations still use lunar calendars like Islam.

Others use a lunar-solar calendar, which is the Julian calendar or our calendar, but also the Jewish calendar.

And so there's always this approximation between trying to get a cycle of a year to match the positions of the sun, the moon, and the stars.

Every single culture has its own calendar to suit its own needs.