John Gill Commentary 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 ordinance." — Nehemiah 8:18 (ASV)

Also day by day, from the first day unto the last day, he
read in the book of the law of God
That is, Ezra; this was done by him every day during the feast, whereas only the first and last days were the holy convocations on which it seems to have been read:

and they kept the feast seven days, and on the eighth day was a solemn
assembly, according to the manner ;
prescribed in (Leviticus 23:39) .