*This post was written mostly with apprentices in mind. Use the charts and info I have included to cross reference the knowledge needed. Winter solstice (From Latin solstitium, from sol ‘sun’ + stit- ‘stopped, stationary’) is an astronomical phenomenon marking the shortest day and the longest night of the year. In the Northern Hemisphere this is the December solsticeThe equinox occurs twice a year. The vernal equinox happens around March 21, when the sun moves north across the celestial equator. The autumnal equinox occurs around September 22nd or 23rd, when the sun crosses the celestial equator going south. The word equinox comes from Latin and means “equality of night and day.”