Reference

Nehemiah 8:18

Also day by day, from the first day unto the last day, he read in the book of the law of God. And they kept the feast seven days; and on the eighth day was a solemn assembly, according unto the manner.
16

So the people went forth, and brought them, and made themselves booths, every one upon the roof of his house, and in their courts, and in the courts of the house of God, and in the street of the water gate, and in the street of the gate of Ephraim.

17

And all the congregation of them that were come again out of the captivity made booths, and sat under the booths: for since the days of Jeshua the son of Nun unto that day had not the children of Israel done so. And there was very great gladness.

18

Also day by day, from the first day unto the last day, he read in the book of the law of God. And they kept the feast seven days; and on the eighth day was a solemn assembly, according unto the manner.

Counter-Arguments

The strongest case that this verse does not belong in this theme.

First Day of the Week

The verse explicitly states "from the first day unto the last day" in reference to the reading of the law, and "on the eighth day was a solemn assembly." It does not mention "the first day of the week" but rather the first day of the festival and the eighth day following it.