What is "d'aoust"

Daoust, D'Aoust, Deault or Dault is a common French language surname, people with this family name can be found in most of Canada (especially in Quebec, Eastern Ontario), the United States and Belgium. It literally translates as (born) in August or (born) in Summer. Although others suggest that it means someone from the village of Aouste in the Ardennes region of France, near Laon. The D apostrophy would indicate being of (de) Aouste, as the Italians use 'di' as in Di Maggio.