If you want to worship under the law of Moses, yes. But those laws were "fulfilled" and "nailed to the cross" blotted out" by Christ. But, Paul said, if you want to still keep it, then keep it for God, but if you don't, the don't do it for God.
Christians are not required to observe the Sabbath. The inspired Christian writings state that “Christ is the end of the Law” (Ro 10:4), which results in Christians’ being “discharged from the Law.” (Ro 7:6) The Scriptures plainly state that Christ’s sacrifice “abolished . . . the Law of commandments consisting in decrees” and that God “blotted out the handwritten document against us, which consisted of decrees . . . and He has taken it out of the way by nailing it to the torture stake.” It was the complete Mosaic Law that was “abolished,” “blotted out,” taken “out of the way.” (Eph 2:13-15; Col 2:13, 14) Consequently, the whole system of Sabbaths, be they days or years, was brought to its end with the rest of the Law by the sacrifice of Christ Jesus. (excerpt from http://wol.jw.org/en/wol/d/r1/lp-e/1200003778?q=sabbath&p=par)
The Sabbath, or the period from Friday night to sundown Saturday, was accepted by the Jews at Sinai. Jews committed themselves to the laws of Moses, and committed their sons and daughters for all eternity. So if you are Jewish, the Sabbath is holy. If you are a Gentile, you can observe a day of rest, but you are not bound by a contract. Its voluntary.