I already told you if you want to be accurate about it go by the lunar calendar we in america go by the solar calender they went by the lunar caldender for them sundown was when the day oficially ended while the next one began while for us that moment is midnight soin a way yes it is saturday by our calendar but on theirs it is sunday
I didin't learn this by some text or anything special I learned it by studying the jewish traditions in fact so much of the bible is written specifically in jewish form much of what Jesus himself said was said in a way for jews because he knew it was what they were accustomed to even just the breaking of the bread was very symbolic to them it was very deep and profound.
The Sabbath isn't based on a lunar calendar - that was the "Feast Days" aka "the Sabbaths of the Jews".
However, the "Sabbath of the Lord" which is "besides" the sabbaths of the Jews (Leviticus 23:38 KJV) is based on the repeating 7 day cycle established in Eden which the Naval Observatory issued a report saying the cycle has never been interrupted. Besides, if it got lost from Eden, God told Abraham who kept all God's statutes, laws, commandments, etc. If it got lost from Abraham, God told Israel. If it got lost from Sinai, Jesus straightened it out, and it's been the same 7 day weekly Sabbath ever since.
But, people ain't as confused as they want us to believe, because if I told a Sunday keeper I'd have a million dollars for him next Sabbath, he'd be there