"Nedelya" doesn't refer to the first day of the week, at least not now. It means is "week". I can see how it may have meant "do-nothing" and also refer to the rest day, but it doesn't place it at the front of the week.
Monday (ponedelnik) splits into "po" and "nedelya". "Po" is a repetition indicator, not "after", so it's more of something that happens every week.
As I've said - Tuesday is "2nd day", Thursday is "4rd day" and Friday is "5th" (pyatnitca - pyat - five). So 3 days out of 7 point at the start of the week being Monday. These names date to the ancient times, not something Soviets invented.
Wednesday ("sreda") does mean "middle day", but it refers to the middle of the work week, excluding Saturday and Sunday, which are named after Christian events and (likely) extended the original 5-day week.
So if you are to argue that a week that has 1st, 2nd, 3rd and 4th days literally spelled out starts on its 7th day, the only explanation would be that Russians used 0-based indexing for the week days. Which is alright with me even if somewhat far-fetched.
PS. Also, the calendar reform was not a move against the religion, but because Russia Empire was literally 13 days behind the rest of the world, which was not very convenient.
Thanks for the link. It had another interesting fact:
> In 1978, the UN recommended that Monday be made the first day of the week in most countries. It was established in 1988, according to ISO 8601, an international standard for exchange and communication of date and time-related data.
I’m really curious about why the UN made that decision. Is this the primary reason so many countries now consider Monday the first day?
Saturday as the Jewish Sabbath, Sunday as the ‘the Lord’s day” in Christianity.
Matthew 28:1
The Resurrection
[1] Now after the Sabbath, toward the dawn of the first day of the week, Mary Magdalene and the other Mary went to see the tomb.