Today is one of the optimum days of the year. Because the sun is overhead at the tropic of Capricorn. So that it is the shortest daylight hour in the north and longest in the south. compared to 12 hours of the equator the temperates daylight hours are much longer than that of the tropics. as a result the optimum day of the tropics is called Tahisas 12, when the temperates is called December 21