The Equation of Time is the bridge between planetary motions/cycles and timekeeping but only as a close proximity rather than an exact relationship. It is not the core principle as it all depends on the greater relationship which formats the 1461 rotations for 4 orbital circuits into 3 cycles of 365 rotations and 1 cycle of 366 rotations rather than the pure proportion of 365 1/4 rotations for 1 orbital circuit.

The precise engineering that makes watches possible is matched by the exquisite principles which mirror the motions of the Earth however the external references for timekeeping develop in sequence and few if anyone has the discipline to consider where it all began ,at least in written form -

"On account of the precession of the rising of Sirius by one day in the course of 4 years therefore it shall be, that the year of 360 days and the 5 days added to their end, so one day shall be from this day after every 4 years added to the 5 epagomenae before the New Year" Canopus Decree, 236 BC