The "Seventh Angel" is mentioned in these passages in the Book of Revelation. The timing of each described event is subject to the opinion(s) of the Reader
Revelation 10:5-7: - 5 The angel whom I saw standing on the sea and on the land raised up his hand to heaven 6 and swore by Him who lives forever and ever, who created heaven and the things that are in it, the earth and the things that are in it, and the sea and the things that are in it, that there should be delay no longer, 7 but in the days of the sounding of the seventh angel, when he is about to sound, the mystery of God would be finished, as He declared to His servants the prophets.
NKJV
Revelation 11:15-19: - Seventh Trumpet: The Kingdom Proclaimed
15 Then the seventh angel sounded: And there were loud voices in heaven, saying, "The kingdoms of this world have become the kingdoms of our Lord and of His Christ, and He shall reign forever and ever!" 16 And the twenty-four elders who sat before God on their thrones fell on their faces and worshiped God, 17 saying:
"We give You thanks, O Lord God Almighty,
The One who is and who was and who is to come,
Because You have taken Your great power and reigned.
18 The nations were angry, and Your wrath has come,
And the time of the dead, that they should be judged,
And that You should reward Your servants the prophets and the saints,
And those who fear Your name, small and great,
And should destroy those who destroy the earth."
19 Then the temple of God was opened in heaven, and the ark of His covenant was seen in His temple. And there were lightnings, noises, thunderings, and turmoil, and great hail.
NKJV
Revelation 16:17-21: - Seventh Bowl: The Earth Utterly Shaken
17 Then the seventh angel poured out his bowl into the air, and a loud voice came out of the temple of heaven, from the throne, saying, "It is done!" 18 And there were noises and thunderings and lightnings; and there was a great turmoil, {WW1} such a mighty and great turmoil {WW2} as had not occurred since men were on the earth. 19 Now the great city was divided into three parts, {1948} and the cities of the nations' fell. {WW1} And great Babylon was remembered before God, {1926} to give her the cup of the wine of the fierceness of His wrath. 20 Then every island fled away, and the mountains were not found. 21 And great hail from heaven fell upon men, each hailstone about the weight of a talent. Men blasphemed God because of the plague of the hail, since that plague was exceedingly great.
NKJV
It is my opinion that the Time of the Gentiles will be completed in around 20 years from now after which God will begin Gathering the Israelites to Himself beginning at the start of the Seventh Age.
Shalom