Parallel
Nehemiah 6:15
Brenton's English Septuagint · Berean Standard Bible
So the wall was finished on the twenty-fifth day of the [month] Elul, in fifty-two days.
So the wall was completed in fifty-two days, on the twenty-fifth of Elul (note: Elul is the sixth month of the Hebrew lunar calendar, usually occurring within the months of August and September.).