We think the following passages are of great importance: “The stone which the builders rejected is become the head of the corner. This is Jehovah’s doing; it is marvellous in our eyes. This is the day which Jehovah hath made; we will rejoice and be glad in it” (Ps. 118:22-24).
“Be it known unto you all, and to all the people of Israel, that in the name of Jesus Christ of Nazareth, whom ye crucified, whom God raised from the dead, even in him doth this man stand here before you whole. He is the stone which was set at nought of you the builders, which was made the head of the corner” (Acts 4:10-11).
Here the phrase is found “the stone rejected by the builders.” Who decides whether a stone is usable or not? It is the builders. If the mason says that a certain stone is unfit to build the house, you do not need to ask anybody else. Whatever the builder decides is final. But a strange thing happened. The stone which the builders rejected became the head of the corner. God put upon it the most important responsibility. What the builders considered useless, God made the chief cornerstone. This is the Lord’s doing. It is marvelous in our eyes. It is indeed marvelous. Verse 24, however, gives us an added marvel related to the Lord’s day. “This is the day which Jehovah hath made; we will rejoice and be glad in it.” The day which the Lord has appointed is the day when the stone rejected by the builders became the chief cornerstone.
It is a day when we will rejoice and be glad. All should fear God and rejoice in His presence. Let us, then, find out what day it was when the stone rejected by the builders became the head of the corner. This we discover in Acts 4:10-11. Verse 10 says, “Whom ye crucified, whom God raised from the dead.” Verse 11 continues, “He is the stone which was set at nought of you the builders, which was made the head of the corner.” In other words, this is the day of the resurrection of the Lord Jesus. God, not man, determined the day when He who was rejected by men was to be raised from the dead. Let there be no confusion. The Bible puts it very clearly that this is the day the Lord has made. What day is it? It is the day of resurrection. So let all the children of God gather in the name of God’s Son on that day and be glad.
Do you see the difference between the Lord’s day in the New Testament and the Sabbath day in the Old Testament? The latter is negative, full of “shalt not’s” and the threat of the punishment of death; the former, though, is a day of great rejoicing. - Nee
After 3 days and 3 nights would be Sunday since the "next day" (Matt 27.62) is a second day, and the third day is the Day of the Lord which is Sunday.