The Winter Solstice, or Midwinter, is celebrated around the world by a variety of cultures. It marks the shortest day of the year (the longest night), and when the sun is at its lowest on the horizon. This usually occurs around December 21-22 in the Northern Hemisphere. From that point onwards, the days continue to grow longer until Midsummer in June. In Celtic countries, the Winter Solstice was seen as a time of rebirth and renewal, as signified by the return of the light.