Those great days from May Day to Lammas.

The Sky This Week, 2012 May 1 – 8 — Naval Oceanography Portal

May 1st is one of the four so-called "cross-quarter" days that hearken back to traditional calendars of medieval times. These days, along with the seasonal markers of solstices and equinoxes, were the traditional days when serfs paid rent to their feudal masters. Most of these "mid-season" dates are now forgotten, but we still unwittingly observe them in various cultures. Americans are quite familiar with Halloween and Groundhog Day, but May 1st isn’t widely observed on our side of the Atlantic Ocean. However, May Day is still widely celebrated in Europe, especially in countries with a strong Celtic tradition. The fourth cross-quarter day, Lammas, falls around August 1st and is probably the least observed of these traditional times. You can think of May Day as the middle of spring or as the beginning of summer. Either way we are now in the time when the length of daylight exceeds 14 hours, which it will do until early August.

The Sky This Week, 2012 May 1 – 8 — Naval Oceanography Portal