Julius Caesar created the modern calendar in 46 BC, and it was adopted by Rome in 45 BC.
His Julian Calendar of 365.25 days added winter months that were previously inconsistent, and used leap days to keep the seasons and the calendar in alignment.
The current form is also called the Gregorian Calendarfor Pope Gregory XIII, who in October 1582 introduced the adjustment of the Julian calendar by skipping 10 calendar days, recognizing that the year was actually slightly shorter than 365.25 days. This calendar removes the leap days from end-of-century years (e.g. 1800, 1900) unless the first 2 digits are evenly divisible by 4.
The calendar was technically first invented by the Ancient Egyptians.
the Gregorian calendar
it wasnt
The Gregorian calendar was an adaptation of a calendar proposed by Aloysius Lilius in 1582. However, the calendar is named after Pope Gregory XIII who introduced this calendar by a papal bull. It was a reform to the Julian calendar.
Properly speaking, there is no "English" calendar system. You probably mean the predominant Western Calendar (also called the Christian Calendar). This calendar system is best called the "Gregorian Calendar", after Pope Gregory XIII who introduced the calendar system in 1582.
The calendar was technically first invented by the Ancient Egyptians.
No, Jesus did not invent the calendar. The modern calendar system in use today (the Gregorian calendar) was created centuries after Jesus' time, in the 16th century. It is based on the solar calendar introduced by Julius Caesar in 45 BCE.
George Washington invented the lunar calendar
The exact calendar that we used today was created by Pope Gregory XIII in the mid-1700s. The original basis for this calendar was the Julian Calendar (the difference between them was the timing of leap years) and the Julian Calendar was invented by Julius Caesar, Emperor of Rome.
the Gregorian calendar
The name of the person that invented the first calendar is not known. The first calendar was invented in Scotland.
China
It is not known who invented the lunar calendar. However, the ancient Chinese are among the first people who begin using a lunar calendar.
The Egyptian
There was an ancient Egyptian calendar, but modern Egypt uses the Coptic Calendar, which is based on the calendar of ancient Egypt.
Rome
The Romans invented it in 46 ad.