How to fit the Middle Eastern Judaeo-Christian festivals i with the Northern European festivals designed around astronomical milestones was always going to create an uneasy balance for people who had celebrate events since remote antiquity in a specific way and time.

Even today, the Americans create the quarter divisions of the seasons by temperature fluctuations whereas the Northern Europeans, at least on the Western islands of Europe, fix the year by daylight/darkness swings. For this reason November 1st signaled the dark half of the year while May 1st signaled the light half of the year so any disputes between American and European designations for fall or winter are resolved within this light/dark half cycle.

The trees lose their leaves at the same time across the Northern hemisphere so November 1st was considered the point when nature goes dormant while May 1st is when nature is in full bloom and all things are made new.

The half light/half dark cycle is just a byword for the Polar day/night cycle and the surface rotation parallel to the orbital plane behind that experience. It brings together two different perspectives into one and should be cherished for those who feel this time of year stir in their bodies.