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 adjusted 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 |
| 31 | 124650 | 2.187 | 24 – 25 April |
| 32 | 1206775 | 21.171 | 17 – 23 April |
| 33 | 1330000 | 23.333 | 10 – 16 April |
| 34 | 1330000 | 23.333 | 3 – 9 April |
| 35 | 1302450 | 22.850 | 27 March – 2 April |
| 36 | 406125 | 7.125 | 22 – 26 March |
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, 1943 and 2011. The next occurrences (up to 2500) will be in 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.
Occasionally, one of the Christian feast days in or just before the Lenten season can fall on the leap day in February. From a liturgical point of view, this does not heighten or modify the character of the event but from a calendrical point of view it may be useful to single these out.
The following table lists these coincidences in the Dionysian/Julian reckoning (years from 532 to 1582) and in the Gregorian reckoning (years from 1583 to 5000) assuming that the leap day is reckoned as the last day in February (29 February).
| Coincidences with 29 February (a.d. pridie kal. Martias) | ||||
| Feast Day | Dionysian | Gregorian | Dominical Letter |
Easter Sunday |
| Sexagesima Sunday | 672, 1204 | 3784, 4088, 4156, 4224, 4376, 4528, 4680, 4748 | DC | 25 April |
| Shrove Sunday | 588, 868, 952, 1036, 1120, 1400, 1484, 1568 | 1604, 1688, 1756, 1824, 1976, 2060, 2128, 2280, 2348, 2432, 2584, 2652, 2720, 2804, 2888, 2956, 3024, 3176, 3260, 3328, 3480, 3548, 3632, 3852, 3920, 4004, 4860 | DC | 18 April |
| Ash Wednesday | 624, 708, 792, 876, 1156, 1240, 1324, 1408 | 2096, 2468, 2688, 2840, 2992, 3212, 3296, 3364, 3432, 3584, 3668, 3736, 3804, 3888, 3956, 4040, 4108, 4192, 4260, 4328, 4412, 4496, 4564, 4632, 4784, 4868, 4936 | AG | 15 April |
| Quadragesima Sunday | 532, 616, 700, 784, 980, 1064, 1148, 1232, 1316, 1512 | 1632, 1784, 1852, 2004, 2088, 2156, 2224, 2376, 2460, 2528, 2680, 2748, 2832, 2984, 3052, 3120, 3204, 3288, 3356, 3424, 3576, 3660, 3728, 3880, 3948, 4032, 4184, 4252, 4320, 4404, 4488, 4556, 4624, 4776, 4928 | DC | 11 April |
| 2nd Sunday in Lent | 644, 728, 812, 896, 1176, 1260, 1344, 1428 | 1920, 2488, 2860, 3232, 3384, 3452, 3604, 3688, 3756, 3824, 3976, 4060, 4128, 4280, 4348, 4432, 4584, 4652, 4720, 4804, 4888, 4956 | DC | 4 April |
| Oculi Sunday | 560, 756, 840, 924, 1008, 1092, 1288, 1372, 1456, 1540 | 1660, 1728, 1880, 1948, 2032, 2184, 2252, 2320, 2404, 2556, 2624, 2776, 2928, 3080, 3148, 3520, 4460, 4832, 4984 | DC | 28 March |
The following table lists these coincidences in the Dionysian/Julian reckoning (years from 532 to 1582) and in the Gregorian reckoning (years from 1583 to 5000) assuming that the leap day is reckoned as in the traditional Roman calendar (24 February).
| Coincidences with 24 February (a.d. bis VI kal. Martias) | ||||
| Feast Day | Dionysian | Gregorian | Dominical Letter |
Easter Sunday |
| Sexagesima Sunday | 648, 732, 816, 900, 1180, 1264, 1348, 1432 | 1924, 2864, 3236, 3388, 3456, 3608, 3692, 3760, 3828, 3980, 4064, 4132, 4284, 4352, 4436, 4504, 4588, 4656, 4724, 4808, 4892, 4960 | FE | 20 April |
| Shrove Sunday | 564, 844, 928, 1012, 1096, 1376, 1460, 1544 | 1664, 1732, 1884, 1952, 2036, 2104, 2188, 2256, 2324, 2408, 2492, 2560, 2628, 2780, 2932, 3084, 3152, 3304, 3524, 4464, 4836, 4988 | FE | 13 April |
| Ash Wednesday | 600, 684, 768, 852, 1132, 1216, 1300, 1384 | 2072, 2292, 2444, 2596, 2664, 2816, 2968, 3036, 3188, 3272, 3340, 3408, 3492, 3560, 3644, 3712, 3796, 3864, 3932, 4016, 4168, 4236, 4304, 4388, 4472, 4540, 4608, 4692, 4760, 4844, 4912, 4996 | CB | 10 April |
| Quadragesima Sunday | 592, 676, 760, 956, 1040, 1124, 1208, 1292, 1488, 1572 | 1608, 1692, 1760, 1828, 1980, 2064, 2132, 2284, 2352, 2436, 2504, 2588, 2656, 2724, 2808, 2892, 2960, 3028, 3180, 3264, 3332, 3484, 3552, 3636, 3704, 3788, 3856, 3924, 4008, 4092, 4160, 4228, 4380, 4532, 4684, 4752, 4904 | FE | 6 April |
| 2nd Sunday in Lent | 620, 704, 788, 872, 1152, 1236, 1320, 1404 | 2092, 2464, 2684, 2836, 2904, 2988, 3056, 3208, 3292, 3360, 3428, 3580, 3664, 3732, 3884, 3952, 4036, 4104, 4188, 4256, 4324, 4408, 4492, 4560, 4628, 4780, 4864, 4932 | FE | 30 March |
| Oculi Sunday | 536, 984, 1068, 1516 | 1636, 1704, 1788, 1856, 2008, 2160, 2228, 2380, 2532, 2752, 3124 | FE | 23 March |