The Silent Winter
As Midgard followers converted to Christianity [weakening Midgard’s ties to other Realms], the health of Jotunheim – the land itself and its ability to provide for the Jotuns – nosedived. Insufficient harvests and drought drove many Jotuns to over-rely on hunting and took too large a chunk out of the prey populations in the Realm as it happened year after year. Some storytellers refer to these few years as the Silent Winter because many Jotuns Who found a way to survive did not wish to talk of what They had to do to accomplish this (murder and cannibalism).
Priests and diviners struggled to figure out what was going on. The points of connection between Jotunheim, Midgard, and Vanaheim that had been feeding the land had weakened to the point that the usual sacrifices and rites were no longer enough. Someone was chosen among those still strong enough and Who could behave diplomatically – Angrboda – to travel to Vanaheim for aid. It took divination, political maneuvering, and more than one session of meetings to fully address the problem and come to a solution.
The Jotuns can call on land magic and bless the land, but They are not specialists in this area of magic as the Vanir are. Additional holy days and rites would have to be added to the yearly calendar of holy days, Someone may have to act as a yearly Sacrifice, or the Vanir would need to play a more active part in healing the land. The holy calendar was similar to how it appears now (eight days), and priests were very sure that trying to schedule in additional rites and sacrifices would not be feasible (particularly when livestock and game populations needed time to recover from too much harvesting).
Many Tribes were adamantly opposed to having a yearly Sacrifice. Between fighting with the Aesir, the kidnapping and removal of three high ranking Jotun children (Fenrir, Hela, and Jormundgand), and the Bindings of Fenrir and Loki, many were under the impression that the Jotuns had sacrificed or were forced into giving up more than enough for the well-being of Everyone else. It was decided that Jotunheim would need to improve its relationship with Vanaheim, so that the land blessing of Vanaheim could trickle to Jotunheim.
This was accomplished in a few ways. Representatives of a Tribe in Vanaheim were incorporated into a few holy days to add an element of Vanic oomph to the proceedings. A Hare appears in the Bones of the Prey (autumn equinox) and the Howls of Spring (spring equinox), and a Deer appears in the Cleaning of Antlers (Aug 1st). Depending on how the health of the land and political relations are going, ambassadors and Dignitaries would need to increase the frequency of visits in order to strengthen to the connections between the Realms.
Angrboda often visits Vanaheim in the lead up to the harvest festival in Jotunheim, and due to the priority on seafood at that time of year, Njord often visits Jotunheim on behalf of the King and Queen (ceremonial roles recently passed on) on the day of. In Jotunheim, the main rite to bless the harvest happens on the Cleaning of Fishbones (summer solstice) rather than lining up exactly with the Vanic harvest blessing (Feast of the Fallen on Aug 1st). In the immediate aftermath of the Silent Winter, Frey was often asked to visit in order to very specifically bless the land and heal it.
The rules and laws on travel between the Realms were adjusted so that it was easier for Vanir to visit as tourists, as ambassadors, and to move to Jotunheim. Many Vanir who visit or run businesses do so in the Capital, but there was also an encouragement in the immediate aftermath of the Silent Winter for Jotun / Vanir couples to stay within Jotunheim for a certain amount of time rather than moving to Vanaheim. Many couples had previously opted to move so that the Vanic partner could interact with family and in the activities of the Vanic holy days more easily, so adjusting the travel laws and encouraging celebrations within Jotunheim would help.
It was around this time that the equivalent of television and broadcasting the proceedings of holy days began. Designated locations within the Tribes (extended of course to the Families in Niflheim and Muspelheim) and the Capital had the tv equivalents, so that citizens who were not attending the rites at the Henge could still participate. (These tv equivalents are reserved for broadcasting holy rites / activities and emergency messages.)
Priests who weren’t involved in the rites at the Henge would do modified rites at the designated locations, provide candles, and help to channel the energy of the citizens towards the goal of the rite. The rites in Vanaheim were broadcast as well for a year to help with the efforts of having Vanir within Jotunheim celebrating within the Realm and benefiting the land.