Thirteen

import datetime
import calendar
from collections import defaultdict

weekdays = defaultdict(int)

start = datetime.datetime(1500, 1, 1)
end = datetime.datetime(2023, 12, 31)

current = start
while current <= end:
    if current.day == 13:
        weekday = current.weekday()
        print(current.strftime("%B %d, %Y") + " - " +
              calendar.day_name[weekday])
        weekdays[weekday] += 1

    current += datetime.timedelta(days=1)

print("\nWeekday counts:")
print("Monday: ", weekdays[0])
print("Tuesday: ", weekdays[1])
print("Wednesday: ", weekdays[2])
print("Thursday: ", weekdays[3])
print("Friday: ", weekdays[4])
print("Saturday: ", weekdays[5])
print("Sunday: ", weekdays[6])