There is an equality of understanding in Earth's orbit that 'area' of space between Sol and Earth in relation with its 'velocity' of travel is equal at all places of the orbit.
Don't lose sight of the fact the Mayans were able to discern an understanding of Earth's orbit without the benefit of advanced knowledge.
How did they do that?
Any guesses?
How did any scientist before the time of telescopes discern the rotation of Earth?
By watching the movement of the stars in relation to time and Earth's reaction in the seasons of the year. The Mayans would have been watching the stars pass by in relation to the sun rise and sun set and would find faster movement across the sky by constellations when Earth was closest to Sol.
