Why is the concept of 'that day' important in Zechariah?

'That day' is a recurring phrase in Zechariah, signifying a future time of divine intervention and fulfillment of God's promises. It often relates to the establishment of a new order and the arrival of the Messiah. Commentators like Matthew Henry interpret this as speaking to the times of the Gospel, showing that the coming of Christ brought a new era of worship, as alluded to in John 4:21-24, where Jesus declares a new way of worship in spirit and truth. This impending time not only signifies judgment for the unrighteous but also the restoration of God's people, signifying hope and renewal.