From the experts:
Solstice graduated from word to official first name when author Lionel Shriver used it for a character in her novel Big Brother. But of course, there were people named Solstice before: six little girls were given the name in the U.S. in 2012. The word solstice is derived from the Old French and Latin term meaning "point at which the sun seems to stand still." There are pagan celebrations around the time of the winter and summer solstices, June 21 and December 21, the longest and shortest days of the year.