The ancient Norse pagan holidays, like many facets of Heathenry, varied greatly from place to place. We have records of the Norse people celebrating holidays based on a lunar calendar, or moon phases, rather than a solar calendar. Some Heathens choose to observe these lunar holidays while others choose to observe holidays that are more accessible.
There’s no fixed or widely-regarded Norse Pagan calendar, but many norse pagans share two holidays: Midsummer and Jül (Yule). These fall on the summer and winter solstices, respectively. Others may also acknowledge the equinoxes. Typically, larger groups will have set holidays for community engagement and celebration.