Parallel
Revelation 9:15
Patriarchal Greek New Testament (1904) · Berean Standard Bible
καὶ ἐλύθησαν οἱ τέσσαρες ἄγγελοι οἱ ἡτοιμασμένοι εἰς τὴν ὥραν καὶ [εἰς] τὴν ἡμέραν καὶ μῆνα καὶ ἐνιαυτόν, ἵνα ἀποκτείνωσι τὸ τρίτον τῶν ἀνθρώπων.
So the four angels who had been prepared for this hour and day and month and year were released to kill a third of mankind.