Several methods are used by the primitive agriculturist to determine the time for planting, the most reliable of which is the position of the sun and moon on the horizon rising or setting. The movements of the latter, especially the phases of the new moon, although important, do not serve as the best basis of the annual calendar. The time of the year cannot be told by observations of the moon. The phases of the moon play a certain rôle among agricultural people, since this planet takes a subordinate place in determining the calendar. The positions of the sun, or the points of its rising and setting on the horizon and its altitude at midday, afforded the primitive agriculturist data that could be relied upon from year to year to determine the season. The position of the sun at midsummer and midwinter, rising or setting, is associated with most important events; the winter solstice indicates the time when the fields should be prepared for cultivation; when the irrigating ditches should be cleared out and prepared for planting. We consequently find the winter solstice, which occurs at the close of December, is practically set aside by all agricultural people as an occasion of a great festival in which sun-worship is dominant. At this time we also find a complicated ceremony, the object of which is to draw back the sun and prepare the people for the work before them. Around this midwinter festival were crowded rites of the purification of the earth from evil influences of winter, a dramatic personation of the return of the sun god, preliminary to the call to the husbandman to begin his work. The planting itself occurs somewhat later, or when the sun reaches the vernal equinox, the determination of which is less important than the solstice.