when were Haggai and Zechariah active and working as prophets?

  Drawing on the assigned reading from Petersen, when were Haggai and Zechariah active and working as prophets? How does this historical context help us understand why both prophets encourage the (re-)building of the temple in Jerusalem? Also, look at the final verses of Haggai (2:20-23). Who is Zerubbabel and, according to Haggai, why is this figure so important?