First Day of the Week

The starting day of the week varies globally, with some regions beginning on Sunday and others on Monday or Saturday.

Origin of the 7 Day Week

The seven day week has no basis in any astronomical phenomenon and for a while, different cultures had varying lengths of time that made up a week. The ancient egyptians had a ten day week while while the Etruscans followed an eight day work week that was initally adopted by the Romans. In 321 CE, the emperor decreed that the Roman empire would be following the seven day week and slowly this standard was adopted around the world.

The seven day week has no basis in any astronomical event and for a while, different cultures had varying lengths of time that made up a week. The ancient egyptians had a ten day week while while the Etruscans followed an eight day work week that was initally adopted by the Romans. It is theorized that the Babylonians based their week on the seven celestial bodies (Sun, Moon, Mercury, Venus, Mars, Jupiter and Saturn) and neighboring territories began to adopt the unit as well.

Beginning of the Week

While all modern day cultures agree on the length of a week, the starting day has some variation around the world.

Many countries with Catholic/Protestant origins begin their week on Sunday, influenced in part by the Sabath being on Sunday. Influenced by Islamic traditions, the first day of the week is Saturday in many Middle Eastern and North African countries while the majority of Europe begins their week on a Monday. The International Organization for Standardization (ISO) counts Monday as the first day of their week for recordkeeping.