World Calendars
Old Icelandic calendar date today
The old Icelandic calendar splits the year into a summer half and a winter half and counts the weeks of each. Its months always begin on the same weekday.
Wednesday in week 3 of winter
Day 19 of Gormánuður
- In the Gregorian calendar
- Wednesday 11 November 2026
- This day began
- At midnight, as Wednesday 11 November 2026 begins
- This day ends
- At midnight, as Thursday 12 November 2026 begins
- Year Winter 2026-27 began
- Thursday 23 April 2026
- Next new year
- Thursday 22 April 2027 (in 162 days)
- This year has
- 364 days in 12 months
- Rule in force since
- 28 November 1700, the change to the Gregorian calendar; no year count of its own
- Who uses it
- Icelanders, for traditional days such as the First Day of Summer and Þorri
- How it works
- 12 months of 30 days plus 4 extra days, with a leap week every 5 to 7 years
- Years count from
- No year count; the calendar has no era and no New Year's Day
- Unusual detail
- Dates were given by week of summer or winter, never as "1 Harpa"
Next holidays in this calendar
162 days
First Day of Summer (Iceland) Thursday in week 1 of summer
22 April 2027 · Old Icelandic
How the old Icelandic calendar works
The year has 364 days, which is exactly 52 weeks: twelve months of 30 days and four extra days called aukanætur, placed in the middle of summer. Because the year is a whole number of weeks, each month always starts on the same day of the week. To keep pace with the seasons, an extra week called sumarauki is added after the extra days every five or six years, and very rarely after seven.
The year is divided into two halves, summer and winter. Summer begins on the Thursday between 19 and 25 April, and winter begins on a Saturday 180 days before the next summer. People reckoned dates by the week of summer or winter rather than by the day of the month, so this page gives each date as a week of summer or winter, such as week 25 of summer.
| No. | Month | Days |
|---|---|---|
| 1 | Harpa | 30 |
| 2 | Skerpla | 30 |
| 3 | Sólmánuður | 30 |
| - | Aukanætur (extra nights) | 4, or 11 with sumarauki |
| 4 | Heyannir | 30 |
| 5 | Tvímánuður | 30 |
| 6 | Haustmánuður | 30 |
| 7 | Gormánuður | 30 |
| 8 | Ýlir | 30 |
| 9 | Mörsugur | 30 |
| 10 | Þorri | 30 |
| 11 | Góa | 30 |
| 12 | Einmánuður | 30 |
Variants and the method used here
We use the rule followed by the Icelandic almanac today. Summer starts on the Thursday between 19 and 25 April, winter starts on a Saturday, and the extra days and sumarauki come after Sólmánuður. Weeks are counted forwards from the first day of each half, starting on Thursday in summer and on Saturday in winter.
Older practice differed. Before 1700 the same rule was tied to the Julian calendar, with summer starting between 9 and 15 April. From the 16th century until 1837 winter was often counted from a Friday, and the printed almanac until 1928 placed the leap week at the end of summer.
The calendar has no year numbers. Labelling each year by the Western year in which its summer began, such as summer 2026 or winter 2026-27, is this site's convention.
A short history
The calendar has been used in Iceland since the time of settlement and was fully developed by the 12th century. Around 955 to 960 a man called Þorsteinn surtr proposed adding a week to every seventh summer to keep the calendar in step with the seasons. Iceland moved to the Gregorian calendar in 1700, when Saturday 16 November was followed by Sunday 28 November, and the summer and winter rules were shifted to match.
The printed Icelandic almanac, published since 1837, still marks the start of each old month and numbers the weeks of summer and winter. The First Day of Summer is still celebrated in Iceland, and the first day of Þorri is known as bóndadagur, or Husband's Day.
Sources
How this site calculates the date: The rule in force since 1700: summer begins on the Thursday from 19 to 25 April, winter on the Saturday 180 days before the next summer; dates are given by week of summer or winter.