
A vast amount of administrative data, and the software that manages that, would have to be corrected/adjusted for the new system, potentially having to support both the IFC and the standard local time keeping systems for a period of time.
If a public holiday is celebrated on January 8, under the International Fixed Calendar that holiday would always fall on a Sunday which is already a non-working day, and compensatory leave would have to be given each year on January 9, thus essentially changing the date of the holiday to January 9. This could be problematic for Public holidays that would fall under non-working days under the new system eg.
Birthdays, significant anniversaries, and other holidays would need to be recalculated as a result of a calendar reform, and would always be on the same day of the week. Christian, Islamic and Jewish leaders are historically opposed to the calendar, as their tradition of worshiping every seventh day would result in either the day of the week of worship changing from year to year, or eight days passing when Year Day or Leap Day occurs. While each quarter would be equal in length (13 weeks), thirteen is a prime number, placing all activities currently done on a quarterly basis out of alignment with the months. Supporters of the International Fixed Calendar have argued that thirteen equal divisions of the year are superior to twelve unequal divisions in terms of monthly cash flow in the economy. Statistical comparisons by months are more accurate, since all months contain exactly the same number of business days and weekends, likewise for comparisons by 13-week quarters. Thanksgiving day, would be able to have a fixed date while keeping their traditional weekday. Movable holidays celebrated on the nth certain weekday of a month, such as U.S. Hence, scheduling is easier for institutions and industries with extended production cycles. The calendar is the same every year (perennial), unlike the annual Gregorian calendar, which differs from year to year.
Every day of the month falls on the same weekday in each month (i.e.Each month has exactly 28 days divided in 4 weeks.Every year has exactly 52 weeks divided in 13 months.The subdivision of the year is very regular and systematic:.The several advantages of the International Fixed Calendar are mainly related to its organization.