Its name originates from the Latin, septimana . The Week is considered as a period of seven days, currently universally applicable as a division of time. This division is artificial, as it was devised by man for our day-to-day distribution. The beginning of the seven-day week is probably due to the division of the lunar month, since the phases of the moon last a period of seven days. It is believed that the origin of the week is from the ancient Hebrews or Jews, since it appears mentioned as a unit of time in the Bible, when in the first book (Genesis) of it the creation of the universe is related, where God worked in six days and on the seventh he rested. However, it is also thought that the Jews took this division of time from the Mesopotamian culture (Babylonians and Sumerians), this culture being the first to use the seven-day week.
In the Roman Empire they used the week in a span of eight days. however, with the arrival of Christianity (of Jewish origins), the Roman week went from 8 to 7 days. Christianity spread little by little in the Roman Empire, and later when the Christian religion was adopted as the official one, the 7-day week was also adopted, thus celebrating the day of rest (Shabbat).
The ancient astronomers took the celestial stars as a reference for the designation of the names of the days of the week (Monday, Tuesday, Wednesday, Thursday, Friday, Saturday and Sunday), in ancient Rome the stars were related to the gods, and in the East with the elements of nature.
In many Christian countries, Sunday is considered the first day of the week. However, according to the international standard ISO 8601, Monday is taken as the first of the days.
