The Calendar that is used by many today was created and invented by the Romans. The calendar did change a lot during Roman times. The Emperor, Julius Caesar had the biggest impact on the calendar.
Romulus created the first Roman Calendar in 753 BC. Romulus created Rome and was a very important ruler.
His calendar had just ten months a year, started in March and was 304 days long. The months had either 30 or 31 days in them. There were 61 days of winter that were not counted in this Calendar.
March – 31 days
April – 30 days
May – 31 days
June – 30 days
July – 31 days
August – 30 days
September – 30 days
October – 31 days
November – 30 days
December – 30 days
The first change to the calendar was around 713 BC under the rule of Numa Pompilius. He added two months to the calendar – January and February. January had 29 days, and February had 28 days.
Pompilius also reduced the days for the months with 30 days to 29 days. The months with 31 days stayed the same. This meant that a year was now 355 days long.
March – 31 days
April – 29 days
May – 31 days
June – 29 days
July – 31 days
August – 29 days
September – 29 days
October – 31 days
November – 29 days
December – 28 days
January – 29 days
February – 28 days
The Romans did notice that the sun could make the year and the days longer. To help with this, Pompilius had a ‘work month’ of 23 days added.
The month would be added between February and March. This could take the full year to 377 days.
Under Julius Caesar, the Roman Calendar changed again in 46 BC. He spoke with his scientists, and they believed that a full year was really 365 and a third.
This meant that a leap day needed to be added every three years. Julius agreed to this and moved the start of the year to January.
This meant that every 3 years a day was added to the end of February. The number of days in the other months stayed the same
When Augustus came to power in 9 BC, he was told that the number of days for a full year was a little bit wrong.
Augustus was told that a full year is really 365 days and a quarter. This meant that an extra day had to be added every four years.