https://www.youtube.com/watch?v=CrB21mc2fmI



Most calenders starts the week on a Monday, not on a Sunday.

Most christians believe the last day of the week is Saturday which marks Sunday as the first day of week but

Exo 20.8
The bible says Saturday is a sabbath day meaning a rest from labour.Originally at Creation, the seventh day of the week was set apart and consecrated as the Sabbath.The seventh day, Saturday, is the only day ever designated by the term Sabbath in the entire Bible..

the commandment to "remember the sabbath day, to keep it holy. and God's blessing of the seventh day (Saturday) as a day of rest.
Today most Christians keep Sundays . The Son of Man is Lord also of the Sabbath” (Luke 6:5). Here Jesus staked His claim and forbade anyone to meddle with the Sabbath.


Dr. William Frederick says: “The Gentiles were an idolatrous people who worshipped the sun, and Sunday was their most sacred day.
When Emperor Constantine I—a pagan sun-worshipper—came to power in A.D. 313, he legalized Christianity and made the first Sunday-keeping law.In the bible you will not find a single line authorizing the sanctification of Sunday. Rome, in concert with the Roman Catholic Church, changed Sabbath to Sunday!

And your point?

Romans 14:5 In the same way, some think one day is more holy than another day, while others think every day is alike. You should each be fully convinced that
whichever day you choose is acceptable.