There was nothing making it a 'holy' day or day of worship in Gods Word, that was brought in by the Roman church to justify the pagan festival of the sun which was easter and this was used to gain more pagan converts who were worshipers of the sun god, and replace the Sabbath as history shows.
Now the fact that Sabbath was supplanted by the church at Rome and even the anti-Judaism stirred up by Jewish revolts is well known and documented, and the claim that came out, that it was from the 'resurrection', one but has to look....
"The author of the "Epistle of Barnabas" adduces the occurrence of the Resurrection on the first day as the reason for the observance of this "true day" (xv.). In the meantime the attitude of the Roman authorities had become intermittently hostile to the Jews; and after the rebellion under Hadrian it became a matter of vital importance for such as were not Jews to avoid exposing themselves to suspicion (Huidekoper, "Judaism at Rome"). The observance of the Sabbath was one of the most noticeable indications of Judaism. Hence, while in the first Christian century more or less regard and tolerance for the Jewish day were shown in Rome, even by non-Jewish Christians, in the second century the contrary became the rule (Justin Martyr, "Dial. cum Tryph." ii., § 28). In the East, however, less opposition was shown to Jewish institutions. Saturday and Sunday both were celebrated by "abstaining from fasting and by standing while praying" (Rheinwald, "Archäologie," § 62), In the West, especially where Roman influence dominated, Saturday was turned into a fast-day (Huidekoper,
ib. pp. 343-344). The name "Sunday" is used for the first time by Justin Martyr ("Apologies," i. 67) in accommodation to a Roman nomenclature, but with reference to the circumstances that the light was created on the first day (noticed also in the Midrash; Gen. R. iii.: "ten crowns adorned the first day") and that the "light of the world" rose from the night of the grave on the first day of the week. The Christians, accordingly, were obliged to defend themselves against the charge of worshiping the sun (Tertullian, "Apologeticus," xvi.). The celebration of two days (by the Judæo-Christians?) is attested by Eusebius ("Hist. Eccl." iii. 37) and by the "Apostolic Constitutions," which advise the keeping of Saturday as a memorial of the Creation, and of Sunday, the Lord's day, in memory of the Resurrection (ii. 59).
Originally, then, Sunday and Sabbath were kept sharply distinct. But, like the Jewish Sabbath, Sunday was deemed not merely a holiday, but a holy day, and hence fasting thereon was interdicted (Tertullian, "De Corona Militis," § 3). Ease of mind (ευφροσύνη, which corresponds to "naḥat ruaḥ"; "Epistle of Barnabas,"
l.c.) was the proper condition for the day. One should not kneel at prayer (Irenæus, "Fragm. de Paschate"; "Apostolic Constitutions,"
l.c.); the standing posture, being at first a protest against mourning and ascetic rites (such as were forbidden on the Jewish Sabbath), came to be explained as suggestive of the Resurrection."....
SABBATH AND SUNDAY - JewishEncyclopedia.com
Some try to say it was changed by the disciples or their actions or the resurrection, but Sunday has nothing even after the resurrection as the disciples continued with the Sabbath as it was before and Christ tells it it would continue so you have to really bend scripture to fit Sunday as the day of worship. It isnt there.......