From Wiktionary, the free dictionary
d'vànt qué
- (Guernsey) before (at an earlier moment in time)
1903, Edgar MacCulloch, “Proverbs, Weather Sayings, etc.”, in Guernsey Folk Lore[1], page 513:I' ne faut pas faire le cottìn d'vànt que le viau seit naï.- One must not make the crib before the calf is born.