Regarding when the Dísting took place, Adam of Bremen places the event at the the vernal equinox, near the first days of summer in the lunisolar calendar. Snorri places it during the Icelandic Gói, and then explains that it was moved to Candlemass. Nordberg explains that Snorri misunderstood his source, noting that the Swedish Göja occured later than the Icelandic Gói. To his mind, Adam’s placement is more accurate, falling right in the middle of the Göja, around the time of the full moon. That the Dísting continued to take place during the full moon of the later Swedish Dístingstungel even after it was moved and Christianized indicates it took place during the full moon. We can confidently move it back to the older, Swedish Göja. The Dísting market and festival originally would have occurred during the full moon nearest the vernal equinox, in the middle of Swedish Göja, Bede’s Hrethmonath. It is interesting to note that this moon occurs a month prior to Eostermonath, and may give credence to Bede’s suggestion that goddesses were also worshiped during the two months encompassing the vernal equinox.
We have scant sources that may reliably give us any picture for what sorts of festivals took place during the heathen midsummer. We know that this time would be important for regulating the lunisolar cycle, and we know that Ólafr Tryggvason moved what had been drinking festivals during this time to Saint John’s Mass, so it must have held some sort of significance at some point prior to conversion. Bonfires have long been associated with midsummer in Scandinavia, and in western Norway they tend to take place around Saint John’s Day, featuring mock marriages called Jonsokbryllup (Jonsok Weddings). Maypoles have been associated with midsummer and can be traced back to the Middle Ages, and in Sweden particular they are still popular. While it is difficult to trace the origins of folk customs, we might see the origins of the maypole in heathen tree/pole worship, as exemplified in the accounts of the Oak of Jupiter (Thor), or the Irminsul,which were both recorded in the 8th century, and have a wider connection to the worship of trees among the heathen. Swedish petroglyphs from the Bronze Age depict figures carrying or dancing around raised poles. At Frösö, the remains of a tree surrounded by the remains of ritually deposited animals correlates with Adam’s description of sacrificed animals hanging from trees in the Uppsala grove, and with the recent finds of posts at Upsalla surrounded by animal skeletons. A seasonal analysis of the bones found at Frösö have demonstrated that the sacrifices most likely took place at three primary times during the year. Around the winternights, around the spring equinox, and at midsummer. So at least in some places, midsummer seemed to be a time for calendrical rituals of some sort, and there is a precidence for hanging offerings from one or more socially significant trees. Throughout Sweden are tricorn stone monuments where ritual deposits and cooking took place, which Stefan Brink argues represented Yggdrasil or some more local cosmic tree. It is therefore reasonable that, like the Halm-Staffan, and the procession of Freyr, the maypole, pole, and tree worship were a part of a common religious tradition. It’s also reasonable to assume some or all of the above elements have played a part in whatever festivities may have taken place on the full moon after the summer solstice, or at the solstice itself.
According to Íslendinabók, in the middle of the 10th century the official Alþingi of Iceland took place “When ten weeks of the summer had passed, and this had been made the law of the land the previous summer, but before this, men had come one week earlier.” This makes the summer Alþingi dependent on the full moon of the month beginning after the vernal equinox, if we go by the lunisolar calendar. However, it is probable that by the time the Alþingi had been established, the shift in calendar from moons to weeks had already begun to take place. While it is possible that Þing events in the middle of summer similar to that of Iceland took place throughout Scandinavia, we must acknowledge that there is a serious lack of evidence. In the Uppland region of Sweden at least during the late Viking Age, the Dísting seemed to have been the time for a national Þing. While we may assert that there is a pattern of celebration and ritual, in the form of bonfires, drinking, and pole or tree customs during the period of midsummer, it is less certain as to whether there were ever large scale festivals as we have seen for the other periods of the year.
In conclusion, the heathen Scandinavians, and probably all Germanic people reckoned time with a lunisolar calendar which was tethered to the winter solstice, occurring between two months which were probably called some variation of Yule. This calendar was maintained by periodically inserting an extra lunar month near the summer solstice. The natural year began on the winternights, which occurred or were celebrated during the first full moon following the autumn equinox. The astronomical year was split into four quarters, each began on, or was celebrated on the first full moon following an equinox or solstice. It is likely that these were the times when annual festivals and religious observations took place, and in the words of Nordberg, they likely “included rituals that alluded to, and in ritual terms repeated, the cosmological creation.” We repeatedly find rituals that mention “ár ok friðr”; something that Simek calls a “formula used in Germanic cult language,” or else we see rituals that serve an identical function. Rituals such as blót would have taken place at these times to mark, ensure, and maintain a successful year. These festivals would have also incorporated any variety of local political and social factors. To put these findings into a hypothetical model of a typical village in southern Sweden in 1000, we might see something similar to what follows over the course of a year.
The veturnætur celebrations occur on the full moon after the autumn equinox, marking the beginning of winter and the seasonal year. On those nights, people pull into their homes, or go to the bigger estates of those who invite them. There would be ritual drinking, and in the evenings, the ritual slaughter and feast of an animal dedicated up to the Dísir, or to Freyr (or both). During the days there would be games, especially at the larger gatherings, where ball games, tournaments, and horse fights might have taken place. If there are public events, bigger rituals involving horses may be dedicated to Freyr, and weddings would take place on farmsteads and at halls. The local Þing assemblies would have been political, but religiously sanctified. In the month following veturnætur, farmsteads would be slaughtering cattle, preparing their stores, brewing, and perhaps participating in prophetic rituals or inviting renowned spámenn/konur to determing how they might better get by the winter and the year to come. As the Yule season progresses (beginning on the second new moon after veturnætur) and midwinter draws near, which is to be celebrated on the full moon a couple weeks after the solstice, the farms would have pulled in and many river courses and travel ways would be closed. One might not cross the fields of the homestead unless they must, for fear of inhospitable weather and stories of trolls or dangerous dead or other supernatural perils; or they might leave offerings out or perform other rituals to keep these spirits at bay; a practice perhaps later replaced by the painting of crosses on church doors in Norway to keep the Oskoriea at bay. The midwinter festivals would occur on the full moon after the solstice, unless it was an embolismic year, and might involve any number of processions or ceremonies involving animal costumes, mock fighting, initiation rituals, and sacrifices to Óðinn, Freyr, Skaði, Þór, Njörðr or whatever god’s cult is strongest in that region, or to any variety of deities, depending on the local aristocracy and social cults, as well as to the dead. Shortly following midwinter, there might be processions for fertility spirits, most notably Freyr, and there might be dramatic rituals performed to try and encourage the return of the sun, and the softening of the earth. Processions of these sorts might continue through the spring, and might involve female deities instead of Freyr. On the full moon closest to the spring equinox, in the month of Göja, the whole district would come together to celebrate the Dísþing with a market, dramas, games, and sacrifices the Dísir, or even one powerful, national Dís. There would be a public þing which would also hold sacrifices and rituals dedicated Freyr or Óðinn or Þór, and the king would participate, distribute gifts, and make oaths. The summer would bring hard work, travel, and trade. There might be rituals to Njörðr, or Þór, or, as is always the case, a region continued to hold particular rituals that centered around the gods that the local shrines or hills or groves were dedicated to. Midsummer might be a time to celebrate the long days, and there might be dancing, decorating and worshiping cult trees or pillars, and there might be big bonfires. With the coming of autumn there would be the harvest, and the festivities centered around that, before the full moon brought winternights and the next year.
This is of course, a fictional model, and a basic, vague one at that; but beyond the timeframes and general themes associated with different times of the year, the nature of calendrical festivities would have varied with time and place. That being said, this article as a whole is hopefully comprehensive enough and establishes enough of a foundation that it will be of value in reconstructing the heathen annual calendar within it’s own context, and will also serve as a map or guide for any researcher trying to place recorded events in written sources into the proper seasonal time frame.
 – Nordberg, 2006, pp. 107-110.
 – See earlier.
 – Gunnell, 1995, p. 136.
 – Robinson, 1916, pp. 62-64.
 – Scholz, 1972, p. 49.
 – Magnell & Iregren, 2010.
 – ArkeologiGamlaUppsala.se (10/18/2013).
 – Magnell & Iregren, 2010, pp. 238-240.
 – Íslendinga Sögur og Þættir, 1987, p. 52.
 – Sundqvist, 2002, p. 100.
 – Simek, 2007, p. 18.
 – Gunnell, 2000.
 – Jens Peter Schjødt, 2008.