Yes tonight is the longest night of the year. Winter solstice marks the total end to the growing season or the start of a new. Key West Fla. Had 10:37 hours of day light today Southern most point of main land USA Bangor Maine had 8:47 hours of daylight Almost the north most point of main land USA. Today we don't pay as much attention to solar changes as our fore fathers did. However in southern year round growing seasons winter solstice is still important in planting and maintaining our plants. Mans relation with plants is from the beginning of our time. The effects of sunlight hours per day could fill the Internet. Every thing from religion to empires has been affected by sunlight.