longest day and longest night

Longest day occurs at the summer solstice, longest night at the winter solstice unless you are close to the poles (within 23.5 degrees or so) when you may have more than one day of either 24 hours daylight/night. The closer you get to the equator the less the difference (day length does not vary at the equator)

longest day is the day you have to sit in a seminar about the ideals of quantum physics as related to energy for 10 hours. the longest night is that in which you have to meet your inlaws for breakfast and dread it so much you cant sleep