“And they were finished.” Dealing with the men who had married foreign women started on the first day of the tenth month and ended by the first day of the first month—so they were completed shortly before the first day of Nisan—so it took almost three months. Dealing with dissolving the marriages of those men and trying to deal with the women and any children would have been a horrible business, with many tears and gut-wrenching decisions. The Bible spares us the details and just tells us the task was handled, but it was certainly not quick or easy.
There is a great lesson buried here in the Word of God: many times because of lack of wisdom or weakness we get ourselves into messes that cannot be straightened out quickly or easily. This can lead to avoiding dealing with the situation, which usually only makes things worse because, as the saying goes, not making a decision is making a decision. Dealing with life in a godly manner often means making difficult decisions and having the fortitude and persistence to see them through until completion. That is what Ezra and the leaders with him had to do.