I typed the word “Sunday” in the search engine at netbible.org and these 9 verses came up:

Mark 16:2 And very early on the first day of the week, at sunrise, they went to the tomb.

Mark 16:9 Early on the first day of the week, after he arose, he appeared first to Mary Magdalene, from whom he had driven out seven demons.

Luke 24:1 Now on the first day of the week, at early dawn, the women went to the tomb, taking the aromatic spices they had prepared.

Rev 1:10 I was in the Spirit on the Lord’s Day when I heard behind me a loud voice like a trumpet,

Isa 52:1 Wake up! Wake up! Clothe yourself with strength, O Zion! Put on your beautiful clothes, O Jerusalem, holy city. For uncircumcised and unclean pagans will no longer invade you.

John 20:1 Now very early on the first day of the week, while it was still dark, Mary Magdalene came to the tomb and saw that the stone had been moved away from the entrance.

John 20:19 On the evening of that day, the first day of the week, the disciples had gathered together and locked the doors of the place because they were afraid of the Jewish leaders. Jesus came and stood among them and said to them, “Peace be with you.”

Acts 20:7 On the first day of the week, when we met to break bread, Paul began to speak to the people, and because he intended to leave the next day, he extended his message until midnight.

1Cor 16:2 On the first day of the week, each of you should set aside some income and save it to the extent that God has blessed you, so that a collection will not have to be made when I come.

Now for the Concordant Literal Translation of these 9 verses:

Mark 16:2

CLV ² And, very early in the morning on one of the sabbaths, they are coming to the tomb at the rising of the sun.”

Mark 16:9

CLV ⁹ Now, rising in the morning in the first sabbath, He appeared first to Mary Magdalene, from whom He had cast out seven demons.”

Luke 24:1

CLV ¹ Now in the early depths of one of the sabbaths, they, and certain others together with them, came to the tomb, bringing the spices which they make ready.”

Revelation 1:10

CLV ¹⁰ I came to be, in spirit, in the Lord’s day, and I hear behind me a voice, loud as a trumpet,

Isaiah 52:1

CLV ¹ Rouse! Rouse! Clothe yourself with your ornaments, O Zion! Clothe yourself in your beautiful cloaks, Jerusalem, the holy city! For no more shall come into you any longer the uncircumcised and unclean.”

John 20:1

CLV ¹ Now, on one of the sabbaths, Miriam Magdalene is coming to the tomb in the morning, there being still darkness, and is observing the stone taken away from the door of the tomb.”

John 20:19

CLV ¹⁹ It being, then, the evening of that day, one of the sabbaths, and the doors having been locked where the disciples were gathered together, because of fear of the Jews, Jesus came and stood in the midst and is saying to them, “Peace to you!”

Acts 20:7

CLV ⁷ Now on one of the sabbaths, at our having gathered to break bread, Paul argued with them, being about to be off on the morrow. Besides, he prolonged the word unto midnight.”

1 Corinthians 16:2

CLV ² On one of the sabbaths let each of you lay aside by himself in store that in which he should be prospered, that no collections may be occurring then, whenever I may come.”

Who can make sense of these two very different versions; one of which proposes a so-called Sunday? On an extremely amusing note, I guess Isaiah 52:1 is included as a reminder to wake up and dress up for church and get circumcised and maybe even take a bath.

In Acts 20 Paul is trying to get to the pilgrimage site of Jerusalem before Pentecost in order to evangelize the diaspora Jews. In 1 Corinthians 16 Paul is not trying to be in Jerusalem for Pentecost. The Corinthian mission to Jerusalem was to help the Jerusalem Jews who had already been evangelized. In both cases, Paul was writing during the Jewish count to Pentecost. It is the spring/summer harvest season, which is why the Corinthian believers can store up a portion of their harvest for Jerusalem. Paul says the Corinthian church should choose trustworthy people to carry their grace/gift to Jerusalem. Paul is collecting support for the new covenant temple of God. He plans to arrive in Corinth some time after Pentecost. He might overwinter in Corinth or he might accompany those who carry their gift to Jerusalem. “one of the sabbaths” in both contexts refers to one of the sabbaths in the 50-day count: from Firstfruit to Pentecost.

Acts 20:5,6,7,16-24

CLV ⁵ Now these, coming before, remained for us in Troas.” ⁶ Yet we sail off from Philippi after the days of unleavened bread, and came to them in Troas in five days, where we tarry seven days.” ⁷ Now on one of the sabbaths, at our having gathered to break bread, Paul argued with them, being about to be off on the morrow. Besides, he prolonged the word unto midnight.”   ¹⁶ for Paul had decided to sail by Ephesus, so that he may not be coming to linger in the province of Asia, for he hurried, if it may be possible for him to be in Jerusalem by the day of Pentecost.”  ²¹ certifying to both Jews and to Greeks repentance toward God and faith toward our Lord Jesus Christ. ²² And now, lo! I, bound in spirit, am going to Jerusalem, not being aware what I will meet with in it, ²³ more than that the holy spirit, city by city, certifies to me, saying that bonds and afflictions are remaining for me.” ²⁴ But of nothing have I a word, nor yet am I making my soul precious to myself, till I should be perfecting my career and the dispensation which I got from the Lord Jesus, to certify the evangel of the grace of God.” 

1 Corinthians 16

CLV ¹ Now, concerning the collection for the saints, even as I prescribe to the ecclesias of Galatia, thus do you also.” ² On one of the sabbaths let each of you lay aside by himself in store that in which he should be prospered, that no collections may be occurring then, whenever I may come.” ³ Now whenever I may be coming along, whomsoever you should be attesting through letters, these shall I be sending to carry away your grace to Jerusalem.” ⁴ Now if it should be worth while for me also to be going, they shall be going together with me.” ⁵ Now I shall be coming to you whenever I may pass through Macedonia, for I am passing through Macedonia.” ⁶ Now, perchance, I shall be abiding with you, or wintering also, that you should be sending me forward wheresoever I may be going.” ⁷ For I do not want to see you at present on the way, for I am expecting to stay some time with you, if ever the Lord should permit.” ⁸ Yet I shall stay in Ephesus till Pentecost, 

The 50-day count to Pentecost was either

1234567,1234567,1234567,1234567,1234567,1234567,1234567,1

or

7,1234567,1234567,1234567,1234567,1234567,1234567,1234567.

Either the types were being fulfilled and put to rest by counting to the consummate first day of the week or the types being fulfilled and put to rest by bringing the chosen people into God’s sabbath rest?

Leviticus 23:15-16

CLV ¹⁵ You will count off for yourselves from the morrow after [after is not in the Hebrew text] the first sabbath, from the day you bring the sheaf of the wave offering: there shall be seven flawless sabbaths. ¹⁶ Until the morrow after [after is not in the Hebrew text] the seventh sabbath you shall count off fifty days; then you will bring near an approach present of new grain to Yahweh.

What is the morrow “after” the first sabbath? Is it when the daytime arrives, which would be the morning of the sabbath, or is it 24 hours after the start of the sabbath, which would be the next night fall? Did Jews start counting at dusk or at dawn? When did the Jews begin counting? Was day one, in the 50-day count to Pentecost, the morning of the first sabbath or the next night? We know they didn’t count the hours of the day until the daytime arrived. The day itself seems to get counted in Genesis when the daytime arrives. And contrary to some misinterpretations, there were no sacrifices at dusk. Sacrifices started in the morning light or at high noon. Never at sunset. “Between the evenings” was after noon and before dusk. The sun starts setting at high noon. All sacrifices were made in the light of the day, whichever day they were counted as being in.

Genesis 1:5

CLV ⁵ And calling is the Elohim the light “day, and the darkness He calls “night.” And coming is it to be evening and coming to be morning, day one.

Mark 16:9

CLV ⁹ Now, rising in the morning in the first sabbath, He appeared first to Mary Magdalene, from whom He had cast out seven demons.”

Jesus rose in the morning of the first sabbath. This first sabbath came after the special sabbath of Unleavened Bread had elapsed, giving the woman a day to buy and prepare the spices. In the context of the Unleavened Bread sabbaths, it is called the second/first sabbath. In the context of the count to Pentecost, it is called the first of the sabbaths or one of the sabbaths or the sabbaths.

The 1st and 7th days of the 7-day feast of Unleavened Bread were special sabbaths and the regular weekly sabbath was usually between them, making it the 2nd sabbath during the feast of Unleavened Bread. Even if it fell on or after the 7th day of Unleavened Bread, it was still the second/first sabbath, because the first sabbath of Unleavened Bread was different than the first sabbath of the Feast of Weeks. That this second/first sabbath was a weekly sabbath is made clear in Matthew 12:1 and Luke 6:1.

Matthew 12:1-2

CLV ¹ At that season Jesus went through the sowings on the sabbaths [the sabbaths refers to the weekly sabbaths in the count to Pentecost]. Now His disciples hunger, and they begin to be plucking the ears and to be eating.” ² Now the Pharisees, perceiving it, say to Him, “Lo! your disciples are doing what is not allowed to be done on a sabbath.”

Luke 6:1

CLV ¹ Now it occurred on the second first sabbath, He is going through the sowings, and His disciples plucked the ears and ate, rubbing them together in their hands.”

Mark 16:1-2

CLV ¹ And, for the elapsing of the [special] sabbath, Mary Magdalene and Mary the mother of James, and Salome, buy spices, that, coming, they should be rubbing Him.” ² And, very early in the morning on one of the [count to Pentecost] sabbaths, they are coming to the tomb at the rising of the sun.”

πρωί 

1) in the morning, early
2) the fourth watch of the night, from 3 o’clock in the morning until 6 o’clock approximately

Matthew 28:1

CLV ¹ Now it is the evening of the sabbaths. At the lighting up into one of the sabbaths came Mary Magdalene and the other Mary to behold the sepulcher.

ἐπιφώσκωto – draw towards dawn

Christmas eve starts at dusk. We arrive to Christmas day in the morning. The only old covenant sacrifice that was done in the dark was when Jesus was arrested in the darkness of that night and then died in the darkened day. The new creation came out of that undone day of chaos into the never ending 7th day, as created by God from the genesis of His very good work week. The last old covenant week of God’s perfect humanity in His Son was cut off in the middle and sacrificed. The darkness lasted halfway through the allotted time they had to sacrifice the passover lambs. That must have created quite the chaos.

Counting to all those typical weekly sabbaths, sabbaticals and special sabbaths was in order to rehearse for and to finally fulfill the deepest meaning represented by the sabbath rest. As Lord of the sabbath, Jesus took His old covenant sabbath rest to His new covenant sabbath rest. He rode into the old covenant Jerusalem on a weekly sabbath, was cut off mid-week and was resurrected into the new covenant sabbath. He sacrificed His old covenant creation for a new one. At the same time, He did a very good work week of re-creation. He transferred His perfection of humanity to an 8th day new covenant. He worked his ‘passion week’ in the image of His Father. Jesus alone was in and would complete His Father’s never-ending 7th day in the old covenant. That is why the new creation week fulfills the 7,1,2,3,4,5,6,7 motif of the types. The original creation week was 1,2,3,4,5,6,7. The 8th day typified a new creation no longer in the flesh. To be in the flesh was to be in the unfinished works mode covenant. Humanity was in the 6th day of creation. Humanity needed to be joined to God in His very good work week. It is the 7th day that is no longer in works mode. The first day is part of the work week. Therefore: 1,2,3,4,5,6,7,1 represents a restart of the work week, rather than God’s sabbath rest. These 8 days are contained by work (maybe even chaos) rather than being contained by God’s very good finished work (an orderly creation or cosmos).

Matthew 11:28-30 ,said Jesus to the Jews in their 40-year re-generation.

JMNT ²⁸ “So everyone come here, toward Me! – all those constantly weary and exhausted from toil and labor, as well as folks having been caused to carry a load, and continuing burdened down – and I, Myself, will refresh you and cause you folks to rest. ²⁹ “At once lift up My crossbeam (or: the yoke which is Me; the balance beam that comes from and pertains to Me) upon you people, and instantly learn from Me, because I am (or: I continuously exist being) mild-tempered (gentle, kind and considerate) and humble (low) in the heart, and ‘you folks will continue finding refreshment and discovering rest in and for your souls (the whole inner person; the mind, emotions and nerves).’ [Jer. 6:16] ³⁰ “You see, My crossbeam (or: the yoke which is Me; the balance beam that comes from and pertains to Me) is useful and kindly obliging, and My load (the burden that is Me and which pertains to Me) continues being light (not heavy).“

Hebrews 4:6-11, to the Hebrews in their 40-year trek to the promised land.

JMNT ⁶ Since, then, there continues being left remaining [for] some folks to enter into it, and those being formerly addressed with goodness (or: being brought a message of ease and well-being) did not enter because of a lack of being convinced (or: incompliance; disobedience), ⁷ again, He is determining (or: He is again defining and setting bounds around) a certain day, “Today!” In David He is saying, after so long a time, just as it has been said before, “Today, if you would hear His voice, you would not be hardening your hearts.” [Ps. 95:7-8] ⁸ For you see, if Joshua caused them to rest, He would not after these things have continued speaking concerning another “Day.” ⁹ Consequently, a keeping of a sabbath (a state of rest) is being left remaining for (or: to; in; with) God’s people, ¹⁰ for the person entering into His rest also caused himself to rest from his own works (actions; deeds), just as God [did] from His own. ¹¹ We should at once with diligence hasten, then, to enter into this rest (or: that ceasing down [from work]; completely stopping), so that one would not fall in the same example (or: result of a pattern) of incompliance (or: stubbornness; disobedience; lack of conviction; [p46 reads: lack of faith and trust]).

Hebrews 4:9 was written to diaspora Hebrews in the last days of their transition. They were about to enter the sabbath rest of their antitypical promised land.

Hebrews 4:9 ECB ⁹ So a shabbatism remains to the people of Elohim.

7,1,2,3,4,5,6,7

Hebrews 1:1-2

CLV ¹ By many portions and many modes, of old, God, speaking to the fathers in the prophets, ² in the last of these days speaks to us [Hebrews] in a Son, Whom He appoints enjoyer of the allotment of all, through Whom He also makes the eons;”

In Son whom He appoints heir of all. Jesus took the place of Adam in His/his death and was resurrected as firstborn of the new creation. We find rest in Him as the firstborn who will never fall.

Colossians 1:15-20

LITV ¹⁵ who is the image of the invisible God, the First-born of all creation. ¹⁶ For all things were created in Him, the things in the heavens, and the things on the earth, the visible and the invisible; whether thrones, or lordships, or rulers, or authorities, all things have been created through Him and for Him. ¹⁷ And He is before all things, and all things consist in Him. ¹⁸ And He is the Head of the body, the church, who is the Beginning, the First-born from the dead, that He be preeminent in all things; ¹⁹ because all the fullness was pleased to dwell in Him, ²⁰ and through Him making peace by the blood of His cross, to reconcile all things to Himself; through Him, whether the things on the earth, or the things in the heavens.

Jesus always existed. He was never created. He became firstborn of His new covenant creation after He took the place of Adam in His/his old covenant death. Adam was firstborn of the old covenant. Jesus was born of a woman late into the olded creation He made. He rescued His people from their old covenant destruction. All God’s people know Him in His new orderly arrangement. Jesus was first born into the new Jewish world of humanity. The old authorities rejected Him because they were in the original firstborn of humanity. All the new covenant Jews accepted Him because they were reborn into the new covenant firstborn. The gospel authors never refer directly to Jesus as God’s firstborn, but they do supernaturally realize that He is the Son of God, a title that connects to the theme of the firstborn post-resurrection. Jesus mostly called Himself the son of the human. That was His mission. He was always the Son of God. HE was never the firstborn of humanity. He was born the late son of the human. He was born again as the firstborn of new covenant humanity.

John 1:10

LITV ¹⁰ He was in the world, and the world came into being through Him, yet the world did not know Him [they knew fallen humanity/Adam].

The devil had so succeeded in the corruption of humanity that Jesus called the authorities in the land, “the sons of the devil”. The devil offered that kingdom authority to Jesus Himself as a Son of God/son of humanity, right before He started His ministry to the fallen humanity in the land. The old covenant was put to rest by destruction. The new covenant entered the sabbath rest of their messiah.

John 3:16

YLT ¹⁶ for God did so love the world, that His Son—the only begotten—He gave, that every one who is believing in him may not perish, but may have life age-during.

“-the only” means unique. Begotten is the past participle of beget. He was uniquely given an old covenant body of flesh and blood through a woman. That was a new thing in the land. In Him alone was life to the age of 1000. It was the final jubilee sabbatism (not Sundayism) of Christ that transitioned His chosen ones from the end of the old to the perpetuity of the new. It matters not what day of the week we meet but it does matter what we teach about God’s Word. What did He do?

Hebrews 8:13, to the Jewish pilgrims in their 40-year re-birth into the new firstborn body of Christ

CLV ¹³ In saying “new, He has made the former old. Now that which is growing old and decrepit is near its disappearance.”

Should we hope for the old covenant promised land in flesh and blood or find our rest in the new? Paul was one of the many Jews who were set free from the law by the Son. They were on track for the final sabbatism. Those who didn’t have the Holy Spirit were not His sons and were about to die there second old covenant death in the land.

Romans 8:1-16

YLT ¹ There is, then, now no condemnation to those in Christ Jesus, who walk not according to the flesh, but according to the Spirit; ² for the law of the Spirit of the life in Christ Jesus did set me free from the law of the sin and of the death; ³ for what the law was not able to do, in that it was weak through the flesh, God, His own Son having sent in the likeness of sinful flesh, and for sin, did condemn the sin in the flesh, ⁴ that the righteousness of the law may be fulfilled in us, who do not walk according to the flesh, but according to the Spirit. ⁵ For those who are according to the flesh, the things of the flesh do mind; and those according to the Spirit, the things of the Spirit; ⁶ for the mind of the flesh is death, and the mind of the Spirit—life and peace; ⁷ because the mind of the flesh is enmity to God, for to the law of God it doth not subject itself, ⁸ for neither is it able; and those who are in the flesh are not able to please God. ⁹ And ye are not in the flesh, but in the Spirit, if indeed the Spirit of God doth dwell in you; and if any one hath not the Spirit of Christ—this one is not His; ¹⁰ and if Christ is in you, the body, indeed, is dead because of sin, and the Spirit is life because of righteousness, ¹¹ and if the Spirit of Him who did raise up Jesus out of the dead doth dwell in you, He who did raise up the Christ out of the dead shall quicken also your dying bodies, through His Spirit dwelling in you. ¹² So, then, brethren, we are debtors, not to the flesh, to live according to the flesh; ¹³ for if according to the flesh ye do live, ye are about to die; and if, by the Spirit, the deeds of the body ye put to death, ye shall live; ¹⁴ for as many as are led by the Spirit of God, these are the sons of God; ¹⁵ for ye did not receive a spirit of bondage again for fear, but ye did receive a spirit of adoption [sonship by birth] in which we cry, `Abba—Father.’ ¹⁶ The Spirit himself doth testify with our spirit, that we are children of God;

The redemption of the Jewish body was by way of the Jewish body of Christ. They joined the firstfruit which was Christ on the Pentecost that followed His resurrection as firstfruit. The nations were the rest of creation that joined the sonship by the same Holy Spirit birth. The new sonship was the sabbatism of Christ that was about to be telosed. The Holy Spirit birthed God’s chosen ones into the new family of God before the old Jewish world was destroyed.

Romans 8:21-23

YLT ²¹ that also the creation itself shall be set free from the servitude of the corruption to the liberty of the glory of the children of God; ²² for we have known that all the creation doth groan together, and doth travail in pain together till now. ²³ And not only so, but also we ourselves, having the first-fruit of the Spirit, we also ourselves in ourselves do groan, adoption [son placing or sonship] expecting—the redemption of our body;