Complex sentence: It is the fifth day of the week in the Judeo-Christian calendar as well, and was defined so in the ancient Mesopotamian and biblical calendars.According to the ISO 8601 international standard adopted in most western countries, it is the fourth day of the week.
Split into simpler sentences: It is the fifth day of the week in the Judeo-Christian calendar as well, and was defined so in the ancient Mesopotamian and biblical calendars. But according to the ISO 8601 international standard adopted in most western countries, it is the fourth day of the week.