English Translation
Their assignments were handed in on September 1st.
Google translate: The works were distributed on the first of September.
I think that if the English meaning was assignments then tarefas would be used.
also the verb translation does not seem to be the best.
distribuídos = distributed
entregado = delivered.
Os trabalhos foram entregado no primeiro de setembro.
As tarefas foram fornecido no primeiro de setembro.