Why do people in China celebrate their birthdays according to the old calendar?

Lunar calendar, namely lunar calendar, old calendar, yellow calendar and China traditional calendar.

Gregorian calendar, namely solar calendar, new calendar, national calendar and international calendar.

This question is a bit absolute.

First of all, there are both new birthdays and old birthdays in China society.

Lunar calendar is a traditional calendar in China.

Since it is called tradition, it is also a calendar followed by a large part of people in the past (different nationalities may follow different calendars);

However, with the development of society and the world becoming a global village, more and more ethnic groups use the Gregorian calendar (Gregorian calendar, new calendar);

Of course, in this case, some people will turn to the new calendar that is easier to remember to remember their birthdays (based on the solar cycle, it is the same every year), and a person's social life has used many new calendars;