Albert Barnes Commentary Nehemiah 6:15

"So the wall was finished in the twenty and fifth [day] of [the month] Elul, in fifty and two days." — Nehemiah 6:15 (ASV)

Elul — The sixth month, corresponding to the latter part of August and the beginning of September.

In fifty-two days — Josephus states that the repairs of the wall occupied two years and four months. But Nehemiah’s narrative is thoroughly consistent with itself, and contains in it nothing that is improbable. The walls already existed everywhere when he commenced his task and only needed repairs. The work was partitioned among at least 37 working parties, who labored simultaneously, with material ready at hand, and, despite all threats, uninterruptedly.