Lunar New Year is referred to in China as nongli xinnian 農曆新年 which literally translates to 'agricultural calendar New Year’ or ‘farmers’ calendar New Year’. It can also be referred to as yinli xinnian 陰曆新年 which means ‘lunar calendar New Year’.
The traditional China calendar is called nongli 農曆 (‘agricultural/farmers’ calendar’) or yinli 陰曆 (‘lunar calendar’). Traditional China was an agrarian society, and the calendar was designed primarily to cater for famers needs, so it’s easy to understand why it’s called nongli.
As for the use of yinli to refer to the traditional Chinese calendar, there are two possible reasons in my view, depending on the interpretation of the word yin 陰 in yinli:
1) Yin may refer to the Shang dynasty (ca. 1600-1046 BC), which was also referred to the Yin dynasty in history. It’s believed that Yin/Shang people made the traditional Chinese calendar, although this calendar is also believed to have been created by the Xia dynasty (ca. 2100-ca. 1600 BC), hence the name of xiali or ‘Xia calendar’;
2) An alternative interpretation for using the word yin may be referring to taiyin 太陰, which is an alternative name of yueliang 月亮 or the moon.
In ancient times, countries like Japan, Korea and Vietnam were heavily influenced by Chinese culture. People in these countries adopted culture and customs including the Chinese writing system and traditional Chinese calendar, among others.
The tiger is a ferocious animal and is referred to as baishou zhi wang 百獸之王 or ‘the king of one hundred beasts’. It’s believed that the person who was born in the Year of Tiger tend to brave, strong-willed (or stubborn), pioneering, outspoken, playful, enthusiastic, impulsive, impatient and fearless with a strong sense of justice.
The Year of the Tiger occurs every 12 years. Previous Years of the Tiger include: 2010, 1998, 1986, 1974, 1962, 1950, 1938.
It is believed that those born in the Year of the Tiger should avoid marrying someone born in the year of Snake or Monkey. They will make a good match with people who were born in the years of Pig, Horse and Dog.
In my opinion, it’s actually misleading to refer to the traditional Chinese calendar as ‘lunar calendar’, as it's a somewhat hybrid or combination of lunar calendar and solar calendar, like the Hebrew Calendar.
It would be more accurate to refer to it as ‘lunisolar calendar’ because it’s formed based on the movement of the moon and the sun. This distinguishes it from the Gregorian calendar, which formed on the movement of the sun.
The Gregorian calendar was adopted for civil or public services in 1912 or the first year of Republic of China. The lunar calendar continues to be used into the twentieth-first century for determining the time of sowing, planting, harvesting, or for the days of holding community and calendrical festivals in China.
Lunar New Year may start in February or January because it’s not formed purely on the movement of the sun. Japan abolished the lunar calendar after the Meiji Restoration in favour of the Gregorian calendar, where the Chinese traditional calendar is still used in Korea and Vietnam for determining festivals, to my knowledge.