The Old Icelandic calendar, also known as the Norse calendar or Old Norse calendar, was a lunisolar calendar used by the people of Iceland and other Norse-influenced areas during the Viking Age and Middle Ages. This calendar was based on a combination of lunar and solar cycles, and it divided the year into months based on the phases of the moon.

The Old Icelandic calendar had 12 lunar months, and each month began with the new moon. The names of the months in Old Icelandic are derived from the Old Norse language. Here are the names of the months along with their approximate corresponding modern calendar months:

  1. Þorri (January/February)
  2. Góa (February/March)
  3. Einmánuður (March/April)
  4. Harpa (April/May)
  5. Skerpla (May/June)
  6. Sólmánuður (June/July)
  7. Heyannir (July/August)
  8. Þorri (August/September)
  9. Gór (September/October)
  10. Þegannir (October/November)
  11. Ýlir (November/December)
  12. Mörsugur (December/January)

It's worth noting that while these months had names, the Old Norse calendar was not as strictly defined as modern calendars. The months were often associated with agricultural and seasonal events, and the calendar could vary regionally and over time.

Today, the modern Icelandic calendar aligns with the Gregorian calendar used globally, and the Old Icelandic calendar is primarily of historical and cultural interest.