Who wrote Zechariah:

Following the end of the exilic period, the people of Judah began rebuilding the Temple which had been destroyed when Babylon invaded. However, because of threats from other nations, the building of the Temple was postponed. Eventually the project was abandoned.

The ministry of Zechariah and his younger contemporary Haggai pushed for the rebuilding of the Temple in 520 B.C. Zechariah, being a priest, was concerned with the priesthood and the sanctification of the Jewish people.

Chapters 9-14 take focus off the Temple and upon the coming messiah. While some have argued this section was written by someone other than Zechariah, there is no good reason to believe this. It is more likely chapters 9-14 were written later by Zechariah after the work on the temple began and focusing on the building the temple was no longer necessary.

Zechariah’s concern for the purity and spiritual wellbeing of the Jewish people found in chapters 1-9 also explain the need to remind the Jewish people of the coming Messiah.

Aside from a change in focus, there is no reason to believe anyone other than Zechariah wrote the book of Zechariah.