Indeed, the sabbath day was only appointed for those who differed over it; and indeed your Lord will judge among them on the Day of Judgment concerning what they were differing in it.
Lord has chosen Friday as the Eid (special day) of the week in Islam. The first man Adam and the first woman Eve was created in Paradise on a Friday. They were descended to earth on a Friday. The World Triumph for the believers will be on a Friday. The Doomsday will be also on a Friday. But the Jews who gradually strayed from Adhikr- the Straightpath- transposed the ‘day of the weekly festival’ from Friday to Saturday (Sabbath day). Some Jew fishermen living at Aila sea shore tried to catch fish on Sabbath day which they considered as prohibited. So Lord punished them by transforming them into monkeys as explained in verses 2: 65-66.
Today, the Arabic Quran reading Fujjar among the 999 out 1000 people of Messenger Muhammad are transposing the days of Eid, Ramdhan, Hajj, etc. according to their whims. Thus they become the worst among 1000 communities of the Lord’s creatures as explained in verse 8: 22. See explanation 2: 113, 136; 7: 163-166 and 16: 64.