How old are you if you have been alive for a billion seconds?
If you have been alive for a billion seconds then you have been alive exactly 31 years, 251 days, 13 hours, 34 minutes, 54.7843 seconds assuming there are no leap years in the time you've been alive- which is impossible. A leap year adds 1 day at the end of February on years that are divisible by 4, unless they're also divisible by 100, except when it's also divisible by 400. So, 1900 was not a leap year, but 2000 was. Why are we giving you this info now? We assume there is at least one hipster out there celebrating their "Billionth-second Birthday" and we just wanted to clarify that we still want the cake even if their math is wrong. Source: MIT