The last thing in the world I would do is try to patronize you. I am correcting you on your false interpretation.
The very first words of the chapter are, [Him that is weak in faith receive ye, but not to doubtful disputations. KJV] The more modern International Version says, [Accept him whose faith is weak, without passing judgment on disputable matters.]
Now, do you think the Apostle would actually call the "Day of Rest of The Lord" a disputable matter. No! He would not. He is talking about fast days (singular or plural) and eating or not eating meat. These are the matters of opinion and Paul is saying in verse 3, ["The man who eats everything must not look down upon him who does not, and the man who does not eat everything must not condemn the man who does..] Verse 5, ["One man esteems one day as more important. Another esteems every day alike. Let each man be fully assured in his own mind."] Please read my post #5 again.
Just how in the world you get the idea that Paul is speaking about Sabbath days here completely escapes me. I can only guess that in your zeal to attempt to show that the Sabbath that Paul and the Apostles all celebrated, the Seventh Day, was done away with and this is one of your convoluted verses attempting to show that.
Please forgive me, everyone, for my convoluted sentence structure in the previous post.
In verse one, St. Paul is trying to get his followers to not invite people to fellowship merely to provide a venue or opportunity to quarrel, as some Christians were "weak in faith." Meaning: they were easily scandalized. So Paul brings up the dietary battles still being waged between the Jewish Christians and the Gentile Christians as an example of this. As a *secondary* example, he talks about the "days" at issue here. What does the observance of days have to do with eating experiences? Nothing I am aware of in those days. It has to do with another ground for contention in the early Church: whether the Sabbath was to be observed on Saturday, as the Jewish Christians preferred, or on Sunday, to honor the Resurrection as the Day of the Lord. BOTH of these issues are relevant to his main point in verse one regardling contentiousness for contentiousness' sake among believers. His hearers were sufficiently aware of the contemporary controversy that exhaustive details in setting up his point were not necessary.
Anyway, we're doing a good job emulating the problem St. Paul addresses in verse 1 now ourselves, so I will not elaborate further except to say that my aside comment about the Trinity in post 50 is *exactly* the same kind of "secondary example" that St. Paul employs in Romans 14:5-6.