Who made calendars and time?

The ancient Egyptians created the solar calendar, and our ancestors created the lunar calendar.

At present, the calendars used all over the world are called Gregorian calendar, which is essentially solar calendar. The original solar calendar was founded by the ancient Egyptians. At first, a year was considered as 365 days.

The lunar calendar, also known as the summer calendar, is said to have originated in the Xia Dynasty in China. Very scientific and practical, so it has been passed down to this day. The lunar calendar is divided into four seasons, twenty-four solar terms and annual festivals according to the natural days of the whole year.

Extended data:

The earliest source of Gregorian calendar can be traced back to the Gregorian calendar in ancient Egypt. The Nile is the lifeblood of Egypt, and it is precisely because of the need to calculate the flood cycle of the Nile that astronomy and solar calendar in ancient Egypt came into being. Seven thousand years ago, they observed that after Sirius rose at the same time as the sun for the first time, the Nile began to flood in fifty or sixty days, so they took this day as the beginning of the year and calculated that it was July of 19.

The first year was set at 360 days, and later it was changed to 365 days. This is the first solar calendar in the world. Later, according to the situation of Nile flooding and agricultural production, they divided the year into three seasons, called flood season, winter and summer. Four months per quarter, 30 days per month, 10 days per week, five days per week. The whole year 12 months, plus five days at the end of the year, is the year-end sacrifice day. This 365-day calendar year was determined by observing Sirius, which is called Sirius Year.

It is about 0.25 days away from the tropic year, so the start time of each year is getting earlier and earlier on the calendar. 146 1 calendar year later, each date coincides with the original season, and then gradually leaves. It seems that Sirius year seems to wander around the cycle of the tropic year, so it is also called wandering year and wandering year. The period of 146 1 year is called Sirius period.

Later, the Egyptians discovered through astronomical observation that the real cycle of a year is 365.25, but in order to make Egyptian festivals and worship meetings held at the same time and maintain the "sacred" status of religion, monks prefer to keep the fleeting time. Later, a stone tablet was unearthed with inscriptions in Egyptian and Greek, which recorded an order issued by Emperor Ogid in 238 BC:

Every four years, after the five-day sacrifice day at the end of the fourth year and before the New Year's Day of the following year, another day is added to hold the festival celebration of Emperor Ogid on this day for everyone to remember. Emperor Ogid corrected the defects of the previous calendar, adding a year called a fixed year and other years called indefinite years.

References:

Baidu encyclopedia-Gregorian calendar