"Shabbat (Hebrew: שַׁבָּת, "rest" or "cessation") or Shabbos (Yiddish: שאבּעס) is the Jewish day of rest and seventh day of the week." - Wikipedia
It's no 'coincidence' that Sabbath(7 letters) / Shabbat(7)/Shabbos(7) is observed on the seventh(7) day. Simply counting the number of letters(7) in a word/name/phrase and giving it symbolic meaning(7) is Step 1 of any language's gematria and is most strong in English(7).
The spirit of the Sabbath is for us all to recognize GOD the Creator(7) - YHWH/Yehowah(7) - and this present(7) of our present life. One's regular(7) job should have the Sabbath off, but if one is a pastor, church music director, and even secular(7) jobs that focus on the weekend(7), GOD/God understands.
The observance of the 4 phases of the lunar month being app. 7 days (~7.4 days) each is where the Genasis(7) story of creation in 6 days + resting(7) on the 7th day came from.
"Anytime(7) a concept(7) is connect(7)ed to nature, it's not only logical(7) - it was inevitable."
