I'm going to go ahead and touch that third rail. I hope I am not dragged out back and stoned for saying this. But I have to give you the truth.
There is a LIE governing all modern calendars. "Earth's Rotation Defines Length of Day"
I don't mean to have a Flat Earth debate here. But we cannot ignore that our scripture describes the earth as a stable non-moving creation. Only moved when God shakes it. The clock is in the heavens above (always above) the earth.
The ancients who aligned their structures with celestial events and those who carved their calendars into stone understood the earth stays put while the heavenly luminaries move.
Once the world was deceived about this, our calendars were permanently doomed to be influenced by that lie. The father of lies loves the most damaging ones. Like that lie in the Garden of Eden, some of his lies have nearly permanent impact on mankind. Are minutes and hours really based on 6? Are days really 24 parts? How many days actually complete the year? God's creation never needed leap-days.
I am as soaked in the deception as anyone else. Nonetheless we know the Father of Truth and we have the Word, to show us the Way.