6, 11, 11 is the cycle I believe.
https://www.answers.com/Q/How_often_in_years_do_calendars_repeat_with_the_same_day-date_combinations
6, 11, 11 is the cycle I believe.
https://www.answers.com/Q/How_often_in_years_do_calendars_repeat_with_the_same_day-date_combinations