Where in the Bible is Sunday ordained as a day of weekly worship by the Creator God?

Th first day of the week was specifically when the disciples came to partake of the Lord's Supper (Acts 20:7). It is also the specific day when Christians are commanded to give of their means (1 Corinthians 16:1-4). So, while we must (and GET to) worship God everyday of the week, the first day of the week is special in that it is the only day of the week we have authority to worship God in these two ways.