Heidegger's Bible Handbook: Zechariah: Chronology

4.  An account of the time in which he prophesied.

In the same as that of Haggai, the second year of Darius (concerning which in the observations on Haggai), in the eighth month, and so in one month, and a little more, after the building of the Temple begun by Zerubbabel and Joshua, Zechariah received his first vision, and the rest in the subsequent time.