What system of Calendar reconing was used before BC/AD?

Question

Was a sense of 'Calendar' only thought of by Pope Gregory / with the advent of the Christ / writing of the Bible / the Swiss Clock?

When Julius Ceasar introduced his Calendar in 46 bc he must have called it something else.

The Greeks couldn't have realised they sacked Troy in 1250 bc.

What was their reconing? What question am I asking?

Answer 1

Initially, the Romans didn't refer to years by count.

Instead they spoke in terms of the the Consul serving at that time - so 205 BC was "The year of the consulship of Publius Cornelius Scipio Africanus and Publius Licinius Crassus"

Later, however, they reckoned years "ab urbe condita" - from the founding of the city. Rome was supposed to have been founded in 753 BC, so they counted from then.

Answer 2

"The Solar term (Nijyuusisekki) " was used in Japan. It came from China. A year is separated 24 terms. Its base is "Risshun" (Feb.3) which is the previous day of "Setsubun". Setsubun is the spring day whose daytime (12hours) and night (12 hours) is the same. Rissyun is traditionally regarded as the beginning day of spring. Usually, current Japanese ordinary calendar has aditional date of solar term in each day's blank.

Answer 3

Each civilization had its own calendar ... eg Chinese, Jews, Indian, Mayan etc. There was no universal one.