In the eighth month, in the second year of Darius - This was Darius Hystaspes; and from this date we find that Zechariah began to prophecy just two months after Haggai.
Son of Iddo - There are a number of various readings on this name, ידו Iddo, and עדוא Iddo, both in MSS. and in editions; but they are only different ways of writing the same name.