Sumerian Calendar
Which Is the Oldest Calendar: Sumerian Lunar-Solar Calendar Explained

Discover the oldest known calendar, the Sumerian lunar-solar calendar from Mesopotamia dating back to 21st century BCE.

Seven-Day Week Origins
The Origins of the Seven-Day Week: Who Named Monday to Sunday?

Discover the fascinating history of the seven-day week and the naming of days from Monday to Sunday, rooted in ancient Mesopotamia.