If you feel you must in good conscience keep the Sabbath on a Saturday....then you must do so earnestly lest you sin before God by violating your conscience as per the admonition of Paul concerning the keeping of feasts and of Holy days that were sacred to some but not to others! But to others who may read this reply, the keeping of any Sabbath despite the disagreement over the day...is no good without the Lord of the Sabbath indwelling you via the Holy Spirit. When the Lord of the Sabbath is with you, it is Sabbath time forever! Hail the great high priest Jesus Christ after the order of Melchizidek...the Lamb of God that takes away the sin of the world!(That WORD that is God, having been made Flesh that dwelt amongst us...see also 1 John 4 should you have any other issues with what I just said! Yeshua is the Anointed savior made flesh...the begotten son of the Living God!)
Its not a matter of conscience, but obedience.
Torah is absolutely mandatory, and we need not worry about failing, as he writes his Torah on our hearts.
Paul praised the Colossians for keeping the appointed times, and chastised the Galatians for mixing in the Pharisees’ false commandments of men.
Saturday is not the Sabbath, Yehova’s days are from sunset to sunset. The days of the Roman calendar are all men’s days. Those that keep man’s commandments depend upon man for salvation. Those that keep Yehova’s commandments are saved by his grace through the faith he bestows upon us by writing Torah on our hearts.