For some strange reason this issue comes up a lot in my dealings with fellow Christians, mostly IRL, but also online. And more than is necessary has derailed a fruitful conversation and left it dead in the water, almost exclusively when the other Christian is a hardline believer in Saturday being the Sabbath, and Sunday being such a perversion that it makes them agitated to the point of disengaging.
I'm a relatively new Christian, always seeking to learn more from others regardless of their beliefs, and I find it baffling how often this topic shuts down folks who are typically among the most Bible literate I engage with. I've seen it deflect from great conversations too often. It's just weird to me.
I did some basic research on this, and AFAIK God never handed down a stone tablet establishing a calender, and the Hebrew calender (and early Roman calender) coincided with the earlier Babylonian calender, and the young Christian church began celebrating Sunday to honor the resurrection, and later the Roman Constantine calender established Sunday as the 7th day. Am I missing something? Why do some find it so overwhelmingly necessary to, seemingly obstenately, observe Saturday Sabbath, and WHY does it so often happen to cause these people to get so angry to the point of distraction? Why is following the Constantine calender a perversion, but not the arbitrary Hebrew calendar?
I realize this is just my experience, but it's an overwhelming experience and has often frustrated me. I do not mean disrespect, but I believe the day is not as important as the ceremony being celebrated with the body of Christ and I would like ammunition to evaluate situation better, and frankly argue against it. Without exception, I haven't met a person whose spiritual life has been improved by this belief; it has kept all of them away from church participation as a result. And honestly, their outward spirits reflect that.
Thanks, I'll check back after work in 12 hours, lol.
Apologies for typos and grammar. I'm bad at phones.
EDIT: I ask here respectfully as honestly, some GREAT Christian practitioners and scholars are here. It's a blessing!
In the Bible "Sabbath" always means the same 7th day of the continuous week, except when it's a metonym for the whole week (or when it means an ungodly corruption added to the weekly Sabbath in Is. 1:13). It's now called Friday sundown to Saturday sundown.
In the Bible the 1st day of the week has a limited separate recognition, namely twice a year it is a Mosaic festival (Firstfruits and Pentecost), it becomes a Jewish Saturday-night gathering (havdalah, Acts 20:7 ff.), it is symbolized by many covenant references to the 8th day (e.g. Tabernacles), and it is Resurrection Day and Pentecost Day for Christians as Mosaically prophesied. (Many 7th-day resters forget all this.)
The 1st day gradually, and without much documentation, moved from Saturday dusk to Sunday dawn because it was the same 1st day (both points representing the resurrection day), but Sunday dawn was easier for Gentiles who didn't have a Saturday rhythm naturally ended by a havdalah service.
Rumors that Hebrew or Roman calendars "coincide" with Babylonian are highly exaggerated. All calendars have points of agreement and disagreement, so I'd hold comment on that for specifics. Evidence is that the 7th-day weekly cycle continues uninterrupted since Creation, that Jesus honored it without making any correction to it, and that it remains unchanged today; though the Hebrew calendar has a bit of pagan naming (e.g. Tammuz), that is totally unrelated to this point.
What Constantine established was to rest on "Sunday", but treating Sunday as the 7th day happened later because the earliest Christians rightly recognized it as the 1st and 8th day. Since this rest (now called a limitation to works of piety, mercy, or necessity) is completely different from Jewish rest (a suspension of 39 categories of work related to temple-building), it's actually possible to honor both interpretations of Sabbath without contradiction.
Constantine is indeed also associated with licentious overreach (u/Sonrise2025 notes, but this wasn't his only motivation), and Hillel is indeed also associated with legalistic overreach. Avoid both extremes.
So to answer your question, many conservatives and literalists recognized that the Ten Words don't literally mean anything but the traditional 7th day and regard the church's downplay of that point to be an unnecessary allegoric spiritualization (against what u/Fubardian said). The right response to this dilemma is literally Romans 14 as u/treepainter and u/LoneWulf rightly say: One esteems day above day, another esteems every day alike, let each be fully convinced (neither judging the other). u/Rooks explicates this concept in good detail.
Resters on either day who judge resters of a different day fail Romans 14. Anger to the point of distraction, 1st day against humble 7th-day resters (like Charlie Kirk as u/Sonrise2025 rightly notes), or 7th day against humble 1st-day resters, becomes a sin. Zeal for one's position is fine but, if it cuts against "unity in essentials, liberty in nonessentials, charity in all", then it's divisive. Testing another's ceremonial practices is a nonessential when the practice is much less likely a sin than the testing itself.
Many congregations, 7th-day Baptists (largely faded), 7th-day Adventists (tens of millions), Hebrew Roots (millions), and Messianic Jews (maybe a million), etc., find 7th-day rest refreshing, beneficial, and synchronous, even as it's a challenge to develop a position given the majority church view and such congregations face infiltration from legalists. I'm a Hebrew Roots guy, sold out to Jesus, and it still took me 30 years to be able to say these things. Aside from the benefit of greatly increased appreciation for Hebrew Scripture, a great benefit is the power to share the good news of Messiah with Jewish people uncompromisingly by approaching their own culture as prophesied in Romans 11.
So permit me to apologize on behalf of divisive people, either those legalists who never meant well, or those Jesus people who haven't had the benefit of being given a harmonious solution along lines like the above. It's my job to absorb the backlash against these 7th-day resters and build bridges of understanding so that the truth will prevail and the liars will be rooted out. I trust this is understandable. God bless you too!
To u/PandaMoon17, (1) after throwing out the "spirit of Christmas" almost 30 years ago I was suddenly shocked to discover recently that Haggai and Simeon may have pinpointed the date of Jesus's conception ("nativity") as December 25, 5 BC, and the earliest Christian tradition about this date may derive directly from this point. (Links to full series.) (2) Trees mean many things, but God's first meaning for a girded tree is the Tree of Knowledge. No single forced association can undo another: to the pure all is pure. (3) Jesus (Ie-sous) and Zeus (Ze-us) have no root in common but the male suffix -us, so the English pun has zero historical value. The fish god's name was so off-point I've forgotten it, and AI doesn't know it either; closest find is Babylonian Oannes (imaginatively tied to John). (4) "Son of Man" is code for the Enochian divine figure (Peter and Jude read Enoch); similarity with pagan or Roman tradition is illusory. (5) For Sunday rest or assembly, see above; for Sunday worship, Christians worship Jesus every day. (6) Yes, Saturday, Saturn, and Satan are closely related (your closest hit), which is why I usually use "Sat", "Mar", and other abbreviations, but again to the pure all is pure.
To u/BooniesRedneck, good start. The trick is that Old Testament covenant people didn't live under the law either, they lived by faith (Hebrews 11, from Abel's animal sacrifice onward). The law was not for legalism but to reflect how the faithful, believing person responds to God's grace, all along.