2 verses have
يَوْمَئِذٍۢ
in Edition Uthmani / Al-Ghaashiya (The Overwhelming)

2:88وُجُوهٌۭ يَوْمَئِذٍ خَٰشِعَةٌ

8:88وُجُوهٌۭ يَوْمَئِذٍۢ نَّاعِمَةٌۭ