The Old Icelandic Calendar

Icelandic Date
Frjádagr
17
Mörsugr

The Old Icelandic Calendar is a unique calendar that was used as the civil calendar in Iceland from the 10th to the 18th century. It is a “leap week” solar calendar, which means that, instead of adding a day periodically to keep it in synchronisation with the seasons, an extra week is added. In most years there are 12 months of 30 days, and an extra four days in the middle of summer, called Sumarauki, giving a year of 364 days, i.e. exactly 52 weeks. In leap years an extra seven days are added to Sumarauki to make the year 53 weeks long.

Having an exact number of weeks in the year means that each year begins on the same day of the week. This is also true of the months as well as each month is always the same length. The year is divided into two “seasons”, summer and winter, with 6 months in each season. In 1700 the starting dates of each month were fixed to certain ranges in the Gregorian Calendar and if we start with the first month of summer, Harpa, this always begins on a Thursday between 19th and 25th April. The next month, Skerpla, always begins on a Saturday, and so on. The extra “leap week” is added to Sumarauki as required to keep the year starting on a date in this range, between the third and fourth months of summer.

The following table shows the arrangement of the months with the day of the week that each month starts and the starting dates in the Gregorian calendar for the period 2023-2030.

Month / *Year-> 2023-24† 2024-25 2025-26 2026-27 2027-28 2028-29 2029-30†
Harpa (Thu) 20 Apr 25 Apr 24 Apr 23 Apr 22 Apr 20 Apr 19 Apr
Skerpla (Sat) 20 May 25 May 24 May 23 May 22 May 20 May 19 May
Sólmánuðr (Mon) 19 Jun 24 Jun 23 Jun 22 Jun 21 Jun 19 Jun 18 Jun
Sumarauki (Wed) 19 Jul 24 Jul 23 Jul 22 Jul 21 Jul 19 Jul 18 Jul
Heyannir (Sun) 30 Jul 28 Jul 27 Jul 26 Jul 25 Jul 23 Jul 29 Jul
Tvímánuðr (Tue) 29 Aug 27 Aug 26 Aug 25 Aug 24 Aug 22 Aug 28 Aug
Haustmánuðr (Thu) 28 Sep 26 Sep 25 Sep 24 Sep 23 Sep 21 Sep 27 Sep
Gormánuðr (Sat) 28 Oct 26 Oct 25 Oct 24 Oct 23 Oct 21 Oct 27 Oct
Ýlir (Mon) 27 Nov 25 Nov 24 Nov 23 Nov 22 Nov 20 Nov 26 Nov
Mörsugr (Wed) 27 Dec 25 Dec 24 Dec 23 Dec 22 Dec 20 Dec 26 Dec
Þorri (Fri) 26 Jan 24 Jan 23 Jan 22 Jan 21 Jan 19 Jan 25 Jan
Góa (Sun) 25 Feb 23 Feb 22 Feb 21 Feb 20 Feb 18 Feb 24 Feb
Einmánuðr (Tue) 26 Mar 25 Mar 24 Mar 23 Mar 21 Mar 20 Mar 26 Mar

Leap year in Old Icelandic calendar.

There is no special numbering of the years used in the Icelandic calendar, so the year may be omitted or the current Gregorian year used.

Days of the Week

The days of the week in the Icelandic calendar are as shown in the table below.

– c. 1200 modern Icelandic English
sunnudagr sunnudagur Sunday
mánadagr mánudagur Monday
týrsdagr þriðjudagur Tuesday
óðinsdagr miðvikudagur Wednesday
þorsdagr fimmtudagur Thursday
frjádagr föstudagur Friday
laugardagr laugardagur Saturday

This description of the Icelandic Calendar is not comprehensive. A more detailed account of the structure, usage and history of the calendar can be found here.

Icelandic date widget created using oical.js by Tim Stridman.