This calendar is an original creation by S. Holt, developed over several years of research into pre-Christian Northern European timekeeping. It is not a recreation of any single historical calendar — no such complete record survives — but rather a thoughtful synthesis of available academic work, linguistic sources, and the internal logic of a lunisolar system.
The core idea is simple: the ancestors of the Norse, Germanic, and Anglo-Saxon peoples tracked time by the moon, not the sun. Each month began with the first visible crescent — what this calendar calls the "spark" of the new moon — and the great seasonal festivals were tied to the full moon following each solstice or equinox. This calendar standardises the spark as two days after the astronomical new moon, making it reproducible and consistent across years.
The calendar is published by Drengskapr Viking Spirit, LLC and is offered freely in this form. A full-featured version with calendar integration, event tracking, and customisation is in development.
Two seasons, not four. The Heathen year has only two halves: Winter (the dark half, beginning at Winter Nights) and Summer (the light half, beginning at Sigurblót). The familiar four-season model came later with the Roman solar calendar.
The year begins with Winter Nights. The Heathen year starts with the lunar month whose spark falls after the first new moon following the Autumnal Equinox — roughly October in modern terms. This is when Winter Nights is celebrated.
Months follow the moon. Each of the 12 (sometimes 13) months begins two days after the new moon. Most years have 12 lunar months; approximately every two and a half years, a 13th month is needed to keep the lunar calendar from drifting away from the solar year. That extra month is called Sumarauki (Summer's Extension) in the Northern Hemisphere, and Vetrauki (Winter's Extension) in the Southern.
Blóts follow the solstices and equinoxes. Each of the four great blóts falls on the full moon of the lunar month following the relevant solstice or equinox — not on the solstice/equinox itself. This means the blot date shifts from year to year, as the moon moves against the sun.
Both hemispheres supported. In the Southern Hemisphere, the seasons are reversed. What is the Autumnal Equinox in the north is the Spring Equinox in the south, so the calendar inverts accordingly — Winter Nights in the south falls in April, not October.
The month names used in this calendar are drawn primarily from Old Norse and Old Icelandic sources. Many alternatives exist across different times and regions — the full-featured version will allow users to switch between name sets or create their own.
| Month | Meaning | Season | Approx. Gregorian |
|---|---|---|---|
| HaustManuðr | Harvest Month | Winter | Oct – Nov |
| GorManuðr | Slaughter Month | Winter | Nov – Dec |
| Yulir Tungl | Yule Moon | Winter | Nov – Jan |
| JolManuðr | Yule Month | Winter | Jan – Feb |
| Mörsugur | Fat-Sucking Month | Winter | Feb – Mar |
| GoaManuðr | Gói's Month | Winter | Feb – Apr |
| EinMánuður | First Month | Summer | Apr – May |
| HarpaMánuður | Harpa's Month | Summer | May – Jun |
| SkerplaMánuður | Skerpla's Month | Summer | May – Jul |
| SolMánuður | Sun Month | Summer | Jun – Aug |
| Sumarauki | Summer's Extension | Summer | Jul – Sep (13-month years only) |
| Heyannir | Hay Month | Summer | Aug – Sep |
| Tvímánuður | Second Month | Summer | Sep – Oct |
The four blóts attested in the primary sources are the cornerstones of the Heathen ritual year. Each is celebrated over three days, centred on the full moon of the lunar month following its respective solstice or equinox.
| Blót | Trigger | Meaning & Associations |
|---|---|---|
| Winter Nights | Full moon of the month after the Autumnal Equinox | Marks the start of the Heathen year and the dark half. A time for honouring the dísir (female ancestral spirits), the Vanir, and the harvest. The veil between worlds is thin. |
| Yule / Midwinter | Full moon of the month after the Winter Solstice | The great midwinter feast. Honouring Odin and the Wild Hunt, the return of the sun, and the ancestors. The Yule log, the evergreen, the gift — all find their roots here. |
| Sigurblót | Full moon of the month after the Spring Equinox | The victory blót, marking the start of summer. Sacred to Odin and Freyr, it was a time for warriors to make offerings before the raiding and trading season began. |
| Midsummer | Full moon of the month after the Summer Solstice | The height of the sun's power. A blót for Freyr and the fertility of the land, for good crops, good sailing, and the abundance of summer. Fires are lit and the night is celebrated. |
This is a teaser release. The full version is in active development and will launch with several tiers of features. Here is a preview of what's planned.
It is as historically grounded as the surviving evidence allows, while also being practical and usable. No complete pre-Christian Northern European lunisolar calendar has survived — what we have are fragments: month names recorded by later Christian scholars, references to seasonal festivals in the sagas, and descriptions of the blót calendar in Snorri's Ynglinga saga and similar sources.
This calendar takes those fragments seriously and builds a coherent system around them, using the same underlying logic — lunar months, solar turning points, a year that begins in autumn — that all available evidence points to. Where choices had to be made (such as the "spark" rule of two days after the new moon), they are made transparently and consistently.
Because they are tied to the moon, not to a fixed date on the solar calendar. The full moon of a given lunar month falls on a different Gregorian date each year — just as Easter (which also follows a lunisolar calculation) shifts around the calendar.
This is intentional and historically authentic. The old peoples did not celebrate Yule on December 25th — they celebrated it when the moon was full in the lunar month following the Winter Solstice. The date moved. The moon was the clock.
A blót (pronounced roughly "bloat," from Old Norse) is a sacrificial offering or sacred feast. In pre-Christian Norse and Germanic practice, the blóts were the great communal religious gatherings of the year — occasions for sacrifice to the gods, feasting, drinking, and renewing bonds between the community and the divine.
In modern Heathen practice, blóts take many forms — from formal outdoor ceremonies with mead and offerings, to quiet home observances. The calendar marks them as three-day events (the eve, the main day, and the day after) to allow for different traditions of observance.
The spark is Day 1 of each Heathen month — the beginning of the new lunar cycle. Historically, a new month likely began when the first thin crescent of the new moon was visible after the dark of the moon. This calendar standardises that as two days after the astronomical new moon (the moment of exact conjunction, when the moon is invisible), which reliably corresponds to when the crescent first becomes visible to the naked eye.
The lunar year (12 lunar months) is about 11 days shorter than the solar year. Without correction, the lunar calendar would drift backward through the seasons — Winter Nights would eventually fall in summer. To prevent this, roughly every two and a half years an extra month is inserted. This is called intercalation, and virtually all historical lunisolar calendars (Hebrew, Babylonian, Celtic) use the same technique.
In this calendar, the intercalary month is called Sumarauki (Summer's Extension) in the Northern Hemisphere and Vetrauki (Winter's Extension) in the Southern. It is inserted after SolMánuður, in the heart of summer.
Yes. Toggle the hemisphere selector in the toolbar. The calendar inverts the seasons completely: what triggers Winter Nights in the north (the Autumnal Equinox) is the Spring Equinox in the south, so the year begins in April rather than October. Midsummer falls in January, Yule in July. The moon phases are identical in both hemispheres — only the seasonal associations and blót triggers change.
Not at all. This calendar will be useful to anyone interested in pre-Christian Northern European traditions, folk practices, ancestral timekeeping, or simply a different way of orienting to the year. Many users find that living by the moon — watching it grow and fade each month, knowing which blót is approaching — changes how they experience time in a meaningful way, regardless of their specific spiritual practice.
New moon and full moon dates are calculated using the astronomical algorithms published by Jean Meeus in Astronomical Algorithms (2nd ed., 1998) — the same methods used by planetarium software and astronomical organisations. The solstice and equinox dates use Meeus's Chapter 27 method. All calculations happen in your browser with no external data source required, and are accurate for any year from roughly 1000 CE to 3000 CE.
Yes, that is planned. iOS and Android apps are on the roadmap, to be released after the full web version launches. The apps will share the same calendar engine and data as the web version, so everything stays in sync.
The best thing you can do right now is share the calendar with people who might find it useful — other Heathens, practitioners, students of Norse history, or anyone drawn to the old ways. The more people who use it and give feedback, the better it gets.
If you'd like to support the creator directly: Venmo: @SHolt45 · PayPal: @Holt45
Paid subscription tiers are coming — they will fund ongoing development, server costs, and the mobile apps.
The Heathen Lunisolar Calendar was created by S. Holt and is published by Drengskapr Viking Spirit, LLC. Drengskapr (Old Norse for the quality of being a true, honourable, courageous person — a drengr) is dedicated to authentic engagement with Northern European heritage and spiritual tradition. This calendar is one of several projects in development under that banner.