周岁

noun

one full year of age; nominal age (as opposed to traditional Chinese 'virtual age')

Refers to the actual age calculated from the date of birth, where a child reaches one year after surviving one full year. This contrasts with '虚岁' (virtual age), where a child is considered one at birth and gains a year at each Lunar New Year. When referring to infants, 周岁 often specifically indicates the first birthday celebration.