If you can explain how the pyramids encode the variation, and how it was measured, I'd like to hear about it
The question is somewhat contrived to fit a particular perspective... The pyramids encode Earth's 3 motions, independently. Analyzed, all three unequivocally relate to completion of one circuit, individually. The path of the Sun that traverses the Globe, essentially relates to 360°, which is mutual in origin with the the two independent axial rotations, spin & precession, each comprising one revolution. Combined interactive product: the latter, being directionally in opposition, takes a bite of time from the former, requiring it to rotate almost a minute longer every day, to complete its 360° obligation.
Likewise, interaction with Earth's parabolic path to which it is held by the Sun, two motions described beforehand, produce the Solar day / sidereal day exotics. The direction of travel, in this case, being one. This does not detract from the 360° properties, which radiate from the very core of Earth, outward and respective of Galactic framework.
The definition of 'a day' creates some confusion. Technically, broken down in component form -- individual motion -- the variation is best comprehended. It is in that context that the pyramids instruct. Interaction of variable obliquity with plane of orbit, also produce a combined outcome: climate - this is not encoded by the pyramid but its causeway.
Therefore, it is not so much a case of making numbers fit, as it is vital in comprehending what the core numbers represent -- prior to incurring combined effect -- in context of three individual motions and how such comprise the relationship between the two heavenly bodies - as if they are static respective one another.