The date of Easter Sunday is crucial for the sequence of the Christian liturgical year as many Christian feast days are celebrated at a fixed interval of days or weeks before or after Easter Sunday.
The following table lists the most important days in the Christian liturgical year and their relation with the date of Easter Sunday. Nominally, the dates are given for the current (Gregorian) calendar year, but the dates can be determined for any other year in the Gregorian calendar.
First Advent Sunday is defined as the fourth Sunday before Christmas and formally starts the annual cycle of Christian feast days celebrating the birth and passion of Jesus Christ. During a complete 5 700 000-year Gregorian Easter cycle the number of weeks between Easter Sunday and First Advent Sunday are distributed as follows:
| Weeks | Frequency | % | Easter Sunday |
| 36 | 406125 | 7.125 | 22 – 26 March |
| 35 | 1302450 | 22.850 | 27 March – 2 April |
| 34 | 1330000 | 23.333 | 3 – 9 April |
| 33 | 1330000 | 23.333 | 10 – 16 April |
| 32 | 1206775 | 21.171 | 17 – 23 April |
| 31 | 124650 | 2.187 | 24 – 25 April |
The shortest interval of 31 weeks only occurs when Easter Sunday falls on 24 or 25 April. Since the introduction of the Gregorian calendar this has occurred in 1639, 1666, 1707, 1734, 1791, 1859, 1886 and 1943. The next occurrences (up to 2500) will be in 2011, 2038, 2095, 2163, 2190, 2231, 2258, 2326, 2383, 2410, 2467 and 2478.
The longest interval of 36 weeks occurs when Easter Sunday falls on 22, 23, 24, 25 or 26 March. During the past two centuries this has occurred in 1815, 1818, 1826, 1837, 1845, 1856, 1883, 1894, 1913, 1940, 1951, 1967, 1978, 1989 and 2008. The next occurrences (up to 2100) will be in 2035, 2046, 2062, 2073 and 2084.