Uvaran Holidays

The religion of Uvara has a very close relationship with the solar calendar year. Holy days mark each month and give structure to the year, with particular focus placed on the passing of the seasons.
Local communities and families often have their own festivals or annual ceremonies that are infused with Uvaran religion but carry a local or organization-specific context. A guild, village, clan, noble house, city, kingdom, or region might celebrate an ascended hero, give sacrifices to a local god or spirit, or may engage in their own annual rituals. That said, there is a kind of primacy in the big religion-wide holidays and a sense of sacredness and broader shared community.
See the Stildanian Calendar for a breakdown of the annual cycle of holidays. This includes the Uvaran Holidays, Kivish holidays, and Aentorl (holidays honoring the Lunar Gods that transcend religion). 

Regular Holidays

The Uvaran year begins with the Frelden Festival, which takes place on the spring solstice (typically in mid-March). This is the most important Uvaran holiday, with nearly mandatory participation across occupations and social classes. The Frelden Festival celebrates the rebirth of Ustav and the renewal of the year. It is seen as an essential ceremony for protecting the dead, bringing of-age children into the adult community, and ensuring that the year will be bountiful. The day is known for its fire leaping and ritual dancing. 
Then comes Ertenfelm, a day in April dedicated to Ertinar God of Rain, Freshwater, Fish, Weather, and Journeys. Ertenfelm is an important festival for keeping the freshwater sources clean and ensuring that rain comes in the proper amount. The day is known for its puppet sacrifice.
Then comes Rugenbot, a day in May dedicated to the God Rugon - the beautiful lord of fertility, duty, and plenty. The festival ensures agricultural plenty. The day is spent humbly in acts of charity and community agricultural planning; the evening has a feast and a ritualized defense-play of maypoles representing the world tree. 
Then comes Allmoot day in June, a minor holiday dedicated to the lineage of priests, mages, and spirits who protect the Uvaran community. It is a day of appreciation for Uvaran Priests and a traditional time for apprentice-priests to either begin their apprenticeship or graduate their apprenticeship. The community swears to obey and protect the priests and receive their blessings in return. In the Kingdom of Hain, it is a day of honor for Vetka and other great heroes.
Then comes Olmieron in July, a minor holiday given in thanks for surviving enemies of the faith - perhaps Kivish invasions or Irradiated monsters - and seeking strength to survive whatever comes next year. It is a martial holiday and often one that honors local power structures, as it honors whoever is the military power in the local society. It is often associated with Kragen as well as any spirits who defend the local place. In peacetime, it is an opportunity for the lord of the realm to parade as a benevolent parent figure through their subjects. In wartime, it is a time to pray for those warriors or soldiers who are out fighting. 
Then comes Elkmob at the start of August, also called the First Fruit's Feast. This is a mostly-agricultural holiday devoted to all of the gods and spirits of abundance. It is a way to thank the gods for what has been gained and pray for equal or greater gains the next year. Costumed revelry and feasting abounds after a period of four days of fasting and abstinence. The Gods celebrated vary depending on how the people of that place survive - farmers might celebrate gods of fertility, harvest, and plenty (Rugon, Kragen, Ustav) while a fishing town might celebrate craft and fishing gods (Hadash and Ertinar )
The next Uvaran holiday is also one of the Aentorl (Lunar God holidays): All Moon's Day in September. This is a day honoring the Lunar Pantheon and seeking harmony among them by giving them equal standing and sacrifice at feasting time. 
Then comes Kragintern in October. This is the greatest of all harvest festivals and a day honoring the war-harvest-law-mines Goddess Kragen. This is a day for costumes, mock battles, and the ceremonial defeat of evil by good in religious theater.
Then there is Snowfall, a movable holiday that serves less of a purpose in structuring the calendar year as it does marking seasons in a practical sense. Snowfall, as the name suggests, is a minor holiday marking the first snow that a place sees that year. Snowfall marks the annual death of Ustav, who dies every winter and resurrects every spring. It is a day of mourning and a day to invoke blessings of protection now that the forces of evil can grow unhindered. It is a solemn day of prayer and remembrance. Since Snowfall is weather-dependent, it is worth noting that its usual calendar placement varies from place to place. 
Then comes Silstren in November. This is the day honoring Silsta the Goddess of guidance and fate. There is a costumed light parade this day, and the community guards a sacred flame as they walk, then rest and dine. Silstren protects the community from winter evils and casts out spirits of misfortune.  
Then comes Hadashten is December. This is the sacred day of Hadash, God of crafts and hearth. This is a hearth festival first and foremost, about hunkering down for winter with your neighbors. Isolated households check on each other, exchange cloth, and promise that they will adopt each other's children. Each community is to send their two strongest adults to check on the other families, belting prayerful song. Priests ritually tie down idols or altars of the Gods to prevent evil spirits from stealing them. Craft guilds often hold special celebrations for member-families.
Then comes Varshasten in January. This is the sacred day of Varsha, Goddess of Life, Survival, and childbirth. This is a day of storytelling, community foraging, and charity. It is important to ritually ward against disease or child death.
Last comes Vanoketen in February. This is the sacred day of the First God, Old Man Vanoke - the apathetic and primal God of sky and sea. This day the community shares in baked cakes (often pancakes and blesses the elderly. 

Notable Regional Holidays

The Day of Honors is a regional holiday associated with Hainish Culture in May. This is a day of remembering heroes, and many celebrate by parading statues and relics of fallen champions through the community. This is a day of both fealty and patronage. It is generally a day of cheer, joy, and respect.
Elfentun is a holiday often worshipped by Uvarans in the chaos wastes. It is a day of ringing bells and open doors, when spirits and other non-hostile Irradiated creatures are welcomed into settlements. It is a day of hospitality. Associated with paganism by some.