The great influence of the New Year was religious belief.
Regarding the differences of New Year', such as the Chines New Year, the New Year of the Jews, the New year of Hindus, the New Year of different countries, the great influence is the religious belief.
For example, what we call now the Roman calendar, was influenced by the Romans, especially by Pagan Rome. On the other hand, the calendar of Israel, that is the calendar of the Jewish people. It started when they left Egypt, like what God said in Exodus 12:2. When they left Egypt when Moses was to liberate them, they were leaving the reign of Pharaoh for them to go to the promised land in Canaan, the Lord told Moses and Aaron.
"This month shall be unto you the beginning of months: it shall be the first month of the year to you."
So, the Jewish calendar, which started in the time of Moses, is different from the Egyptian calendar. Why? You can recall that the Egyptian calendar came first because the Israelites sojourned in Egypt for 430 years before the Jewish calendar started. Read Exodus 12:40.
"Now the sojourning of the children of Israel, who dwelt in Egypt, was four hundred and thirty years. And it came to pass at the end of the four hundred and thirty years, even the same day it came to pass, that all the host of the LORD went out from Egypt."
On that very night, the calendar of the Jewish people started. So, their calendar is different from the Egyptian calendar, because they sojourned in Egypt for 430 years, and even before they settled in Egypt, there already was an Egyptian calendar, which is why the Egyptian calendar is older than the Jewish calendar. The same goes with the Roman calendar, the Jewish calendar is older than the Roman calendar. The Chinese calendar is also ancient because the dynasty of the Chinese people in ancient where their calendar started.
So, what we can say is, those calendars and the years being reckoned by cultures and different nations, most of the time, are influenced by their religious beliefs.
That's what I can say about that...