WORLD CIVILIZATION

Detailed explanation-1: -The Babylonians, who lived in modern-day Iraq, were astute observers and interpreters of the heavens, and it is largely thanks to them that our weeks are seven days long.

Detailed explanation-2: -The modern seven-day week can be traced back to the Babylonians, who used it within their calendar. Other ancient cultures had different week lengths, including ten in Egypt and an eight-day week for Etruscans.

Detailed explanation-3: -Chaldean astronomers made one of the first sundials. They also were the first to have a seven-day week.

Detailed explanation-4: -The seven-day week originates from the calendar of the Babylonians, which in turn is based on a Sumerian calendar dated to 21st-century B.C. Seven days corresponds to the time it takes for a moon to transition between each phase: full, waning half, new and waxing half.

Detailed explanation-5: -So the Babylonians used a seven-day week, with the seventh day having certain religious responsibilities (relaxation, cessation of work, worship, that kind of thing).