Although keeping time is a human invention and was only agreed upon relatively recently, variations in the earth's wobble around its axis have lead to shorter and longer amounts of sunlight further away from the equator.

But these variations are part of a long cycle (Milankovitch cycles) on observatories like Newgrange and Stonehenge prove that the position of the sun in the northern hemisphere has been very consistent for the last 10,000 or so years.