A cross-quarter day is a day falling halfway between one of the four main solar events (two solstices and two equinoxes) and the next one. These originated as pagan holidays in Northern Europe and the British Isles, and survive in modern times as neopagan holidays.

The cross-quarter days traditionally mark the start of spring, summer, autumn, and winter, respectively, and are:

• Imbolc or Imbolg (February 1)
• Beltane or Bealtaine (May 1)
• Lughnasadh or Lunasa (August 1)
• Samhain (November 1)

Together with the solstices and equinoxes (Yule, Ostara, Midsummer, and Mabon), these form the eight solar holidays in the neopagan wheel of the year. They are often celebrated on the evening before.

There are Christian and secular holidays that correspond roughly with each of these four, and some argue that historically they originated as adaptations of the pagan holidays, although the matter is not agreed upon. The corresponding holidays are:

• Candlemas (February 2 or February 15), Groundhog Day (February 2) and St.Brigids Day (February 1)
• Walpurgis Night (April 30) and May Day (May 1)
• Lammas (August 1)
• Halloween (October 31), All Saints (November 1), and All Souls Day (November 2)

Each of which see for more on their possible relationship with the pagan holidays.

See also: quarter days