Revelation 8:1

1AndΚαὶwhenὅτανHe openedἤνοιξενtheτὴνsealσφραγῖδατὴνseventhἑβδόμην,there wasἐγένετοsilenceσιγὴinἐντῷheavenοὐρανῷfor aboutὡςhalf an hourἡμιώριον.

And when He opened the seventh seal, there was silence in heaven for about half an hour.