I have calculated the exact time of Imbolc in 2013, to the minute, halfway between the 2012 Winter Solstice and the 2013 Spring Equinox. February 3, 16:07 UT (11:07 a.m. Eastern Standard Time) is the precise Imbolc time between Dec. 21, 2012 11:12 (UT) (Winter Solstice) and Mar. 20, 2013 11:02 (UT) (Spring Equinox).
Imbolc is an important landmark in the seasonal cycle of the year, and many cultures closer to the land than ours have considered it the start of Spring. Imbolc is the traditional festival which has survived in America in the form of Groundhog Day.
The pagan "Wheel of the Year," has eight festivals, composed of the 4 quarter days:
-- The Vernal (Spring) Equinox, when the Sun is aligned with the Equator, and begins the half of the year in the Northern Hemisphere when the daylight is longer than the dark period of night.
-- The Summer Solstice, the longest day of the year and when daylight begins getting shorter each day.
-- The Autumnal Equinox, the counterpart of the Vernal Equinox, when day and night are equal, but now beginning the half of the year when the length of nights will be longer than the days.
-- The Winter Solstice, the shortest day of the year and when daylight begins getting longer each day.
The solstices and equinoxes are the main quarterly changes in the growth, diminishing, and dominance of daytime or nighttime.
The cross-quarter days are the four traditional festivals, each of which falls halfway between two adjacent quarter days:
-- Imbolc, around February 2, has the same daylight ratio as Samhain, but with increasing daylight. Imbolc ends the darkest three months of the year.
-- Beltane, around May 1, has the same daylight as Lughnasadh, but with increasing daylight. Beltane begins the lightest three months of the year.
-- Lughnasadh, around August 1, has the same daylight as Belane, but with decreasing daylight. Lughnasadh ends the lightest three months of the year.
-- Samhain, around November 1, has the same daylight as Imbolc, but with decreasing daylight. Samhain begins the darkest three months of the year.
The modern celebrations of Groundhog Day, May Day, and Halloween are derived from the older festivals of Imbolc, Beltane, and Samhain respectively.
