How to calculate the nominal age?

Nominal age is recorded as one year old at birth and increases by one year every Spring Festival.

One year old is zero at birth, and every Gregorian birthday is one year older. So nominal age is one year older than full age (birthday this year) or two years old (no birthday this year).

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In the ancient legend of China, "Nian" is a monster living in the sea. It has long tentacles on its head, which is fierce and unusual. Every new year's eve, it goes ashore to devour livestock, hurting people's lives.

The legendary "Sui", written as "Chong", is a small demon with black hands and white body who comes out to kill children every 30 nights. One possible explanation is that the ancients recorded by years because they had no abstract concept of time and could only regard years and years as an animal or a monster, but animals and monsters are inseparable, and they can only live for a whole year and only add a whole year. This may be the origin of the Spring Festival.

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