A Saint's feast day falls on whatever day was chosen by the church. It could be a date that has significance to the Saint or a random day.
Pope Benedict I is not a saint and has no feast day.
Saint Maria Goretti's Feast Day is July 6th.
The feast day of saint Mark is April 25.
Saint Christopher's feast day is July 25th.
Saint Laura's Feast Day is October the 19th.
July 24 is the feast day of Saint Charbel.
The 23rd of April is the feast day of Saint George.
Saint Helena's feast day is August 18.
August 11 is the feast day of Saint Philomena.
November 22 is the feast day of Saint Cecilia.
The feast day of Saint Apollonia of Alexandria is on February 9.
The feast day of Saint Anastasia of Sirmium is on December 25.