The solstices and equinoxes have been marked for thousands of years. Samhain, Imbolc, Beltane, and Lughnasadh appear in medieval Irish texts. But the eight-spoked Wheel of the Year as one cycle was assembled in the mid-20th century by founders of modern pagan witchcraft, and names like Litha and Mabon were attached in the 1970s. Each high day here separates the old festival from the modern observance, so you can honor both knowingly.