Fifty-two weeks in a year is not exact. A common year is 365 days, which is fifty-two weeks and one day; a leap year is fifty-two weeks and two. That single leftover day is why a given date moves forward one weekday each year, and it is the reason no calendar of whole weeks can ever be stable without intercalation.
A standard playing-card deck has fifty-two cards in four suits of thirteen, and there is a well-travelled piece of folklore that reads the deck as a calendar: fifty-two cards for the weeks, four suits for the seasons, thirteen cards for the lunations, twelve court cards for the months, and the pip values summing to 364 with the joker making 365. The arithmetic works, and it is worth checking rather than dismissing, the values one to thirteen sum to 91, and four times 91 is 364.
The history does not support the reading. European playing cards arrive from the Islamic world in the late fourteenth century, and early decks are not standardised: fifty-six cards was common, Italian and German decks used different suit systems and different counts, and the fifty-two card French-suited pack settles only in the fifteenth and sixteenth centuries as a commercial and manufacturing convention. The calendrical interpretation is first recorded much later and is a retrospective reading of a structure that arrived for other reasons.
This is a useful test case. The numbers genuinely line up, and lining up is not evidence of intent. The Mesoamerican Calendar Round is a real calendrical use of fifty-two, documented in the sources of the cultures that used it. The card-deck calendar is a coincidence someone noticed, and the difference between the two is the difference between history and pattern-matching.