When Gabriel came

There are only a few times in the Bible in which an angel is named. Gabriel is named twice in the book of Daniel, and twice in the book of Luke. In Daniel, he famously introduces the prophecy of the "seventy sevens" -- the 490 years until the coming of the Anointed. Daniel meets Gabriel in this way:

While I was still speaking in prayer, the man Gabriel whom I had seen in the vision at the beginning, flying swiftly, touched me -- it was about the time of the evening sacrifice. (Daniel 9:21)

In Luke, he is first seen telling Zechariah the priest that his prayers have been heard, that he and his wife will have a child:

According to the custom of the priest's office, his [Zechariah's] lot was to burn incense when he went into the Temple of the Lord. And the whole multitude of the people were praying outside at the time of incense. And an angel of the Lord appeared to him, standing at the right side of the altar of incense. ... And the angel, answering him, said, "I am Gabriel" (Luke 1:9-11; 19)

Zechariah is told that his child, not yet conceived, will fulfill the role of Elijah in the prophecy of Malachi: his child will be the forerunner of the Messiah (compare Malachi 4:5-6 to Luke 1:17).

These are not the only appearances of Gabriel, but they have some interesting similarities: Both times, Gabriel is given the honor of bringing good news related to the coming Messiah. (This occurs again when Gabriel announces Mary's blessing to her, to be the mother of the Messiah.) I wonder if Zechariah, when he found he was talking to Gabriel, might have remembered that Gabriel's last known appearance was the prophecy of the time til the coming of the Messiah, a time he would have expected was reaching its fulfillment. The similarity would have been made stronger in his mind by another aspect of the timing: Gabriel had appeared to Daniel at the time of the evening sacrifice. Here again, Zechariah seems to have been performing either the evening or morning sacrifice (when the incense is offered) at the time that Gabriel came to him. Do angels favor the time of prayer for visiting? For revealing the answer to a long-sought prayer?