Romans Chapter 14 
has nothing to do with the seventh day sabbath.
It is in reference to fast days.

The Pharisees required fasting two days per week.
See Luke 18:12 ...I fast twice in the week....

¹Him that is weak in the faith receive ye, but not to doubtful disputations. ²For one believeth that he may eat all things: another, who is weak, eateth herbs. ³Let not him that eateth despise him that eateth not; and let not him which eateth not judge him that eateth: for God hath received him. ⁴Who art thou that judgest another man’s servant? to his own master he standeth or falleth. Yea, he shall be holden up: for God is able to make him stand. ⁵One man esteemeth one day above another: another esteemeth every day alike. Let every man be fully persuaded in his own mind. ⁶He that regardeth the day, regardeth it unto the Lord; and he that regardeth not the day, to the Lord he doth not regard it. He that eateth, eateth to the Lord, for he giveth God thanks; and he that eateth not, to the Lord he eateth not, and giveth God thanks. ⁷For none of us liveth to himself, and no man dieth to himself. ⁸For whether we live, we live unto the Lord; and whether we die, we die unto the Lord: whether we live therefore, or die, we are the Lord’s. ⁹For to this end Christ both died, and rose, and revived, that he might be Lord both of the dead and living. ¹⁰But why dost thou judge thy brother? or why dost thou set at nought thy brother? for we shall all stand before the judgment seat of Christ. ¹¹For it is written, As I live, saith the Lord, every knee shall bow to me, and every tongue shall confess to God. ¹²So then every one of us shall give account of himself to God. ¹³Let us not therefore judge one another any more: but judge this rather, that no man put a stumblingblock or an occasion to fall in his brother’s way. ¹⁴I know, and am persuaded by the Lord Jesus, that there is nothing unclean of itself: but to him that esteemeth any thing to be unclean, to him it is unclean. ¹⁵But if thy brother be grieved with thy meat, now walkest thou not charitably. Destroy not him with thy meat, for whom Christ died. ¹⁶Let not then your good be evil spoken of: ¹⁷For the kingdom of God is not meat and drink; but righteousness, and peace, and joy in the Holy Ghost. ¹⁸For he that in these things serveth Christ is acceptable to God, and approved of men. ¹⁹Let us therefore follow after the things which make for peace, and things wherewith one may edify another. ²⁰For meat destroy not the work of God. All things indeed are pure; but it is evil for that man who eateth with offence. ²¹It is good neither to eat flesh, nor to drink wine, nor any thing whereby thy brother stumbleth, or is offended, or is made weak. ²²Hast thou faith? have it to thyself before God. Happy is he that condemneth not himself in that thing which he alloweth. ²³And he that doubteth is damned if he eat, because he eateth not of faith: for whatsoever is not of faith is sin.