You are 40 years old if you were born on December 31, 1983.
You are 40 years 2 months, 4 weeks, and 1 day old or 483 months old or 2,099 weeks old or 14,699 days old or 352,776 hours old or 21,166,560 minutes old or 1,269,993,600 seconds old You were born on a Saturday.