june is one of two months to have a solstice (the other is december, its seasonal equivalent in both hemispheres), and in this month the tropic of cancer in the northern hemisphere is turned towards the sun, meaning that june 20 or june 21 is the northern summer solstice and the southern winter solstice. this means that this date would have the most daylight of any day in the northern hemisphere, and the least in the southern hemisphere. there are 24 hours of daylight at the north pole and 24 hours of darkness at the south pole.