A common year starting on Saturday is any non-leap year (i.e. a year with 365 days) that begins on Saturday, 1 January, and ends on Saturday, 31 December. Its dominical letter hence is B. The most recent year of such kind was 2022 and the next one will be 2033 in the Gregorian calendar[1] or, likewise, 2023 and 2034 in the obsolete Julian calendar. See below for more.
Any common year that starts on Wednesday, Friday or Saturday has only one Friday the 13th: the only one in this common year occurs in May.
From July of the year that precedes this year until September in this type of year is the longest period (14 months) that occurs without a Tuesday the 13th.