Sabbath in Noahide Law
Rabbi Yoel Schwartz (Jerusalem Court for Bnei Noah)
A Noahide should not observe the Shabbat in the manner that a Jew does. Nor should he make a point of abstaining from hard physical work on the Shabbat. A Noahide should not give occasion for a Jew to break the Shabbat.
There are those who say that every Ger Toshav (a non-Jew living in Eretz Yisrael in the time of the Jewish Temple, who has formally accepted the obligation to observe the Noahide laws in front of a Jewish court) has to uphold and keep the Sabbath (Rashi, Kritot 9, Yevamot 40). There is room to suggest that the Noahides, even nowadays, by accepting to fulfill the seven commandments, are in the same category as a Ger Toshav and should, according to Rashi, be required or at least allowed to keep the Shabbat. So I (Rav Schwartz) would like to suggest that this is the way that the Noahides could celebrate the Seventh Day, a day of refraining from his vocation. On the eve of the Sabbath (Friday night), they might have a festive family dinner with special food and light candles after sundown in honor of the Seventh Day, which was given to Adam and Noah (and to make the Noahide celebration of the Shabbat distinct from the Jewish Shabbat observance). During the meal they may sing songs to strengthen their belief, including songs about the creation. They may read from the Torah. They should not call this day the Sabbath, but the Seventh Day as it is written in Genesis.
On the Seventh Day itself, if they can arrange it without difficulty, they should refrain from going to work. If possible, they should go out to the fields or a park so as to feel close to the Creator of the world. If the congregation holds a prayer session, they may recite the Psalms connected to the Sabbath and to the creation (like Psalm 104). Also they should study portions of the Torah connected to commandments of the children of Noah. They can study from the weekly portion of the Torah being read that Sabbath in the synagogues those subjects which concern all mankind and skipping those topics that concern specifically the Jews.
At the end of the Sabbath (Motzai Shabbat), the end of the Seventh Day and the beginning of the new week, they can recite the prayer for the new week (Havdalah) after having lit a havdalah candle, to thank G-d for having taught Adam how to make fire, which is the source of all energy that enabled man to make changes in this world. This Havdalah prayer, that separates the Seventh Day from the beginning of the week, can be recited as a Noahide wishes and can go something like this.
Blessed are you our G-d, King of the Universe, Who differentiates between darkness and light, between day and night, between the seventh day from the first day of the week, between the clean and the unclean, between the sacred and secular, between holy days and regular days, between Israel and the rest of the nations, who together are partners in one holy objective, to make Your Name holy in this world. AMEN.
Rosh Hashanah Which is the first day of Tishrei is a day of reckoning for the whole world. The first day of Rosh Hashanah should be a day of repentance and deep inner thought about what a person has done during the past year. A Noahide should recite a prayer requesting that all the people of the world will accept and recognize the truth concerning the one true G-d. A Noahide can recite certain prayers from the Rosh Hashanah prayer book.