At creation, God designed the time between day and night and put the night first - the day next. Backwards from our time. The beginning of night is the beginning of day.
"God called the light day, and the darkness He called night. And there was evening and there was morning, one day." Genesis 1:5 The beginning of night is the beginning of day.
God set this way of counting time for His people 2500 years before there was a Jewish nation.
If God changed this way of speaking of days and nights to His people where is the proof?
Evening is first, then the morning. The night was initiated by the arrival of “complete darkness.” Jesus was buried the evening of preparation day Luke 23, “And that day was the preparation.”
Shouldn’t that have settled it for the Jewish leaders? It should, but it didn’t. One of the days that we have been discussing “Thursday, Nissan 15” was a Holy Day. The Jews called it Passover, although it was actually Nissan 15, the first day of the feast of unleavened bread, not the 14th day of the month which God had designated as Passover. Why were His people so lax with his commands? The Passover lambs had been slain the previous evening - - - - - for those who ignored God’s command and had killed their lambs at that later time - - - - twenty one hours or more after God’s designated time, then roasted and eaten that night, prior to dawn.
No servile work was permitted this day, only the preparation of the food and there was to be no leaven anywhere in their homes for seven days - - - only unleavened bread could be eaten.
Sabbath regulations have been debated for over 3,000 years without an end to the controversy. Scripture has weightier matters as well as matters not so weighty matters, although important. Jesus gave this harsh rebuke: “They bind heavy burdens upon men’s shoulders; but they themselves will not move them with one of their fingers.” Matthew 23.
The burdens that the Pharisees imposed upon their people were their own interpretations of what it meant to keep the law, such as observing the Sabbath. These are preserved in the Mishnah. The Mishnah is more than twice the size of the New Testament and filled with legalisms - - - such as how many letters of the alphabet may a man write on the Sabbath. Two Rabbis disagree as to whether writing two letters of the alphabet would violate the Sabbath.