You can reset the age counter on January 1, and say its my birthday, the remaining days you have before this date can be considered as days, weeks or months! ...
Like if someone is manufactured or born on July 14, then he/she will have to wait till 1st January, that day will be birth day + 7 months and 14 days ( hours/mint/secs) ... on every 1st January she / he can celebrate her / his birthday and can announce I am 21 years, 7 months and 14 days old~
abay yeh kaun see mathematics hai?