Yesterday was the last full day of winter and tomorrow will be the first full day of spring.  Spring officially arrives at 11:06 PM EST tonight.  The Spring Equinox refers to the time that the sun moves across the Earth’s equator, going from south to north.  That signals the first day of astronomical spring in the Northern Hemisphere and the first day of Fall south of the equator. As spring starts, the the length of daylight increases dramatically closest to the Spring Equinox. After that, days still get longer, but at an ever-decreasing rate. On the longest day of the year, the summer solstice, the day-to-day difference reaches zero.  The summer solstice will occur this year on Thursday, June 20th at 4:04 PM.