(Qaaf) 50 : 20
وَنُفِخَ فِي الصُّورِ ۚ ذَٰلِكَ يَوْمُ الْوَعِيدِ

And the trumpet will be blown, that is the Day of Promises.

The Blow in the Trumpet (Swoor) will be happened only after ten crucial signs of Dooms Day are appeared as explained in verse 6: 158. See explanation 36: 51-54; and 39: 68-69.