In another example, a business recently called me to book a job – a day early. This was because they had a calendar with March (and every following month) a day early, probably because it was a Leap Year that year. This wouldn’t have happened using a Fixed Calendar because Leap Days are not a weekday.
Note that the old French Republican calendar, suggested as the solution in Matthew’s article above, appears not to have been researched with the latest offerings in mind. The International Fixed Calendar.