Parallel
Revelation 8:1
Nestle 1904 Greek New Testament · Berean Standard Bible
Καὶ ὅταν ἤνοιξεν τὴν σφραγῖδα τὴν ἑβδόμην ἐγένετο σιγὴ ἐν τῷ οὐρανῷ ὡς ἡμιώριον
When the Lamb opened the seventh seal, there was silence in heaven for about half an hour.