One Day, One-Thousand Years
The seven-day week is not only a rhythm of work and rest. In the Talmud, the Zohar, and the Apostolic writings, it is a scale model of the entire arc of time.
For much of human history, the prevailing assumption has been that the universe is eternal, possessing neither a beginning nor an end.
The Bible asserts that the world was created and was given six thousand years. At the close of that timeline, a cosmic renewal will unfold, drawing the natural order back into its supernatural source.
Hints In Genesis
The tradition finds an early hint in the opening verse of the Torah:
בראשית ברא אלהים את השמים ואת הארץ׃
When G_D began to create heaven and earth
Genesis 1:1-
Six Alephs
As Hebrew letters carry numerical value¹, the Aleph (א) is equal to one. A total of six alephs appear in this opening passage, one for each of the six days of creation.
Six Thousand
Another clue is that the word for "thousand" is Eleph (אלף), written with the identical letters as the word Aleph (אלף). If we read the six Alephs as six Elephs, these six alephs total six thousand.
From this the tradition derives the idea that Heaven and Earth, (space and time as we experience them) will endure for six thousand years.
One Day Equals One Thousand Years
Another hint is found in Psalm 90:
“For in Your sight, a thousand years are like yesterday that has passed, like a watch of the night.” Psalm 90:4
There is a relativistic aspect hinted here. The Sages understood that time on earth was somehow different from time in the upper worlds.
Shabbat and the Pattern of Seven
In the Zohar, it is discussed that the first word of Genesis 1:1, "Beresheit", is can be read as a composite of two Aramaic words: Bara-sheis, which means “He Created Six.” Another allusion to the six thousand years timespan.
This pattern is rehearsed every week through the observance of Shabbat. Here, the six days of labor culminate in the Shabbat. This reminds us that the six millennia will give way to a seventh, that is, the Messianic Era and World to Come².
In essence, the 7-day week is a fractal of the entire arch of time. In the Bible, 7 is the number that represents the natural order of the upper and lower worlds. Hence, we see seven: earths³, Heavens⁴, seas, continents, classical planets, etc.
Below is a timeline, according to the tradition.