The Shabbat idea of a weekly rest day
Who
The Hebrew Bible and Jewish tradition; historians such as Thomas Cahill credit the Hebrews with the notion of a fixed weekly day of rest
When
2nd–1st millennium BCE
Where
Ancient Israel / the Levant
The Sabbath, commanded in the Hebrew Bible, established the revolutionary idea of a recurring day of rest each week for everyone, including servants and animals. Historians such as Thomas Cahill (The Gifts of the Jews) trace the modern weekend and the very concept of protected rest back to this Jewish institution.
Sources
Part of “The Gifts of the Jews” — verified Jewish contributions to the world, with sources.