Disadvantages of Gregorian Calendar
- Due to its development is irregular.
- Is associated with religious beliefs shared only by a segment of humanity.
- The start date corresponds to the wrongly dated birth of Christ.
- Divide the history in an event relevant only for a fraction of humanity.
- Have negative years.
- Do not have zero year.
- The duration of months in the quarters is different as well as the duration of the quarters.
Quarter 1: 31, 28/29, 31. Total 90/91.
Quarter 2: 30, 31, 30. Total 91.
Quarter 3: 31, 31, 30. Total 92.
Quarter 4: 31, 30, 31. Total 92.
- The leap day location at second month end causes the displacement of a date on the day of the week be different if the date is before or after February 29. If before, the double displacement occurs on the year after the leap year. If after, the double displacement occurs on the proper leap year.