Adding to baxtr's comment: first day of spring = days (daylight) lengthening, day and night equal. First day of summer, longest day/shortest night. First day of

Adding to baxtr's comment: first day of spring = days (daylight) lengthening, day and night equal. First day of summer, longest day/shortest night. First day of autumn, days shortening, day and night equal. First day of winter, shortest day/longest night.