Who created months and days?

The concept of months and days has ancient origins, with various civilizations contributing to their development. The Babylonian calendar, for example, divided the year into 12 months based on lunar cycles, while the Egyptians introduced a solar calendar with 365 days. The modern Gregorian calendar, established by Pope Gregory XIII in 1582, refined these earlier systems, standardizing the lengths of months and establishing the seven-day week. Thus, the creation of months and days is a cumulative effort spanning multiple cultures and eras.