'Year' in the Bible

In the eighth month, in the second year of Darius, the word of Yahweh came to the prophet Zechariah son of Berekiah, son of Iddo, saying,

On the twenty-fourth day of [the] eleventh month, the month of Shebat, in the second year of Darius, the word of Yahweh came to Zechariah the prophet, son of Berekiah, son of Iddo, saying,

{And then}, in the fourth year of King Darius, the word of Yahweh came to Zechariah on [the] fourth [day] of the ninth month, [which is] Kislev.

{And then} every survivor from all those nations coming against Jerusalem will go up year after year to worship [the] king, Yahweh of hosts, and celebrate the Feast of Booths.