ᚴᛚᛅᚦᛁᛚᛁᚴᛅᚾ᛫ᛋᚢᛘᛅᚱᛏᛅᚴ
The primstav marks today, April 14th, as Sumarmál or Sommardag (Summer Day): the first day of the summer half of the year!
Old Norse time reckoning, and consequently the Old Icelandic calendar, began the months and seasons on a lunar basis, with summer and the month of Harpa beginning on the third full moon after the Yule moon. This year, that falls on April 26th, just a bit after the primstav reckoning.
Heimskringla mentions that the "onset of summer" was marked with Sigrblót (Victory Sacrifice), which one could assume was held at the actual beginning of the season. Not much else is mentioned in regard to major observances, although this was the time at which people began to bring out their livestock while still watching closely over them. The month's name itself is a woman's name in Old Norse and Icelandic, and as with Þorri and Góa it may have been personified as a goddess or legendary female figure.
Though here in Western Washington (specifically the Cascade foothills) our seasonal transitions are a little more gradual than where these methods of time reckoning originated, yesterday and today have been the first two days absent of frost or rain in a while, so it definitely feels like a seasonal change nonetheless!