Easter
We count fasting or kneeling in worship on the Lord's day to be unlawful. We rejoice in the same privilege also from Easter to Whitsunday. Tertullian (A.D. 198) Ante-Nicene Fathers vol.3 pg.94
You have sent to me, most faithful and accomplished son, in order to inquire what is the proper hour for bringing the fast to a close on the day of Pentecost. For you say that there are some of the brethren who hold that that should be done at cockcrow, and others who hold that it should be at nightfall. For the brethren in Rome, as they say, wait for the cock; whereas, regarding those here, you told us that they would have it earlier. And it is your anxious desire, accordingly, to have the hour presented accurately, and determined with perfect exactness, which indeed is a matter of difficulty and uncertainty. However, it will be acknowledged cordially by all, that from the date of the resurrection of our Lord, those who up to that time have been humbling their souls with fastings, ought at once to begin their festal joy and gladness. But in what you have written to me you have made out very clearly, and with an intelligent understanding of the Holy Scriptures, that no very exact account seems to be offered in them of the hour at which He rose. Dionysius of Alexandria (A.D. 264) Ante-Nicene Fathers vol.6 pg.94
As the case stands thus, we make the following statement and explanation to those who seek an exact account of the specific hour, or half-hour, or quarter of an hour, at which it is proper to begin their rejoicing over our Lord’s rising from the dead. Those who are too hasty, and give up even before midnight, we reprehend as remiss and intemperate, and as almost breaking off from their course in their precipitation, for it is a wise man’s word, “That is not little in life which is within a little.” And those who hold out and continue for a very long time, and persevere even on to the fourth watch, which is also the time at which our Savior manifested Himself walking upon the sea to those who were then on the deep, we receive as noble and laborious disciples. Dionysius of Alexandria (A.D. 264) Ante-Nicene Fathers vol.6 pg. 95
And the other party, passing the day of the Lord’s Passion as one replete with sadness and grief, hold that it should not be lawful to celebrate the Lord’s mystery of the Passover at any other time but on the Lord’s day, on which the resurrection of the Lord from death took place, and on which rose also for us the cause of everlasting joy. For it is one thing to act in accordance with the precept given by the apostle, yea, by the Lord Himself, and be sad with the sad, and suffer with him that suffers by the cross, His own word being: “My soul is exceeding sorrowful, even unto death;" and it is another thing to rejoice with the victor as he triumphs over an ancient enemy, and exults with the highest triumph over a conquered adversary, as He Himself also says: “Rejoice with Me; for I have found the sheep which I had lost."Anatolius Ante-Nicene Fathers vol.6 pg. 149
When Servilius Paulus was proconsul of Asia, at the time that Sagaris suffered martyrdom, there arose a great controversy at Laodicea concerning the time of the celebration of the Passover, which on that occasion had happened to fall at the proper season; and this treatise was then written. Melito (190) Ante-Nicene Fathers vol.8 pg.758
As for us, then, we scrupulously observe the exact day, neither adding nor taking away. For in Asia great luminaries have gone to their rest, who shall rise again in the day of the coming of the Lord…These all kept the Passover on the fourteenth day of the month, in accordance with the Gospel, without ever deviating from it, but keeping to the rule of faith. Polycrates (2nd century) Ante-Nicene Fathers vol.8 pg. 773-774
We would have you know, too, that in Alexandria also they observe the festival on the same day as ourselves. For the Paschal letters are sent from us to them, and from them to us: so that we observe the holy day in unison and together. Theophilus (2nd century) Ante-Nicene Fathers vol.8 pg. 774