Both popes are expected to become official saints on the same day, the Italian news agency ANSA reported.
"This Sept. 30, the pope will hold the consistory of the saints. On that occasion he will announce the dates of the canonizations," Cardinal Angelo Amato, prefect of the Congregation for the Causes of the Saints, said in response to reporters' questions about John Paul.
Francis has already signed the decree making John and John Paul saints, the final step needed for canonization. Polish church leaders have been pressing to honor John Paul in October on the 35th anniversary of his election, but Vatican officials say that does not allow enough time for arrangements.
Dec. 8, the Feast of the Immaculate Conception, is thought to be a likely date for the canonization ceremonies for both popes..