The traditional market and Thing of the Swedes was called Disting, or “Thing of the Dísir.” So it is almost certain that this was when the Swedes held their Dísablót, or their equivalent of the Anglo-Saxon Mothers’ Night, and honored the dísir and their female ancestors in general.
However, Disting seems to have happened in the late winter or very early spring. Adam of Bremen says that the great sacrificial festival at Uppsala was held every ninth year on the vernal equinox (in mid-March), and that the market happened at the same time. According to Heimskringla, the market, which had come to be known as Disting, was held during Gói, the month that began in mid-February and ended in mid-March, and after the conversion was moved earlier to coincide with Candlemas or the Feast of Our Lady (February 2). However, Snorri noted that when he visited Sweden, the moon was full at Candlemas. So there are two possibilities for the timing of Disting. It may have happened at the equinox, in association with the Uppsala festival; or it may have only happened then every ninth year, and otherwise happened on a prior full moon, while winter still lay on the land. The question is whether it would then have taken place on the full moon of Gói or that of the previous month, Þorri (mid-January to mid-February). Some Swedish heathens do celebrate Disting in late January or early February, around the time of the Anglo-Saxon Blessing of the Plough or Eowemeolc; one possible date this year (2006) was the full moon of January 14. But since Snorri says the festival was relocated to Candlemas, the full moon of Gói seems more likely: the full moon that precedes the vernal equinox. The lunar months are late this year: some may celebrate Disting on February 13, but I think March 14 has a better claim.
Doubtless Disting has always had as one of its main purposes asking the ancestors, and the dísir in particular, to bless the farm with a good harvest and the animals with many sturdy young. Also doubtless the early date—the ground is still frozen in Sweden on February 2—made travel to market easier before the spring thaw turned the roads to mud, and avoided too many conflicts with duties at home. All the great public festivals of ancient heathenry combined blót, sumble, and veizla (bletsung, symbel, and húsel) with legal meetings (including lawsuits, judgments, land sales, handfastings, and weddings), trading, and plain ordinary get-togethers between friends. But the dísir are also wise and holy guides for the currently living, and to be revered. A wicked little story, “Gunnar Helmings Þáttr,” tells how a rascal on the run took refuge with the gyðja who was driving an image of Freyr around Sweden in a cart; it’s clear from the story, scurrilous though it was, that this cart procession happened every year and was intended to bless the crops. (Tacitus says the same about Nerthus in Germania.) Probably the cart started on its journey at Disting, going north and being overtaken by more and more signs of spring as it traveled. But the dísir are very much more than fertility spirits, so we should not consider Disting merely a fertility festival.