The difference between Easter Sunday in the Julian and Gregorian calendars
The distribution graph below shows the difference between Easter Sunday in the Julian and Gregorian calendars by the amount of weeks. The difference is always counted by whole weeks, since Easter always occurs on a Sunday, and there are always 7 days per week in both calendars. Also, since the gap between the two calendars increases in the future, the number of matches decreases as well (i.e. the date when Easter will be celebrated at the same time according to both calendars). The next union of Easter dates will occur in 2698. You may also notice the small proportion of three-week differences towards the end of the histogram; the first time this will appear is in 4995.
Each century is arranged by column (based on the value of the Gregorian epact changes), with the sum of the number of individual differences adding up to 100. However, this excludes the first column, since the Gregorian calendar wasn’t introduced until the end of the 16th century.