Birthdays can be celebrated in advance, but not. However, postponing the birthday is against the taboo of geomantic omen. Postponement of birthday is a way to pay homage to the dead, not to celebrate the birthday of the living. Birthday is the birthday when a person is born. When everyone celebrates his birthday, it represents a new life. People attach great importance to birthdays. Birthdays can be advanced, but not postponed. Birthday refers to both the date and the anniversary of a person's birth. Traditionally, China people calculate their birthdays according to the lunar calendar, and children's first birthday is called "one year old", which has various customs.