Age in seconds
Your age in seconds. A billion seconds is about 31 years and 8 months, which is a birthday worth marking and almost nobody does.
How to use the age in seconds
The numbers get large quickly and are more interesting than they sound. A year is roughly 31.5 million seconds, so most adults are somewhere between one and two billion. The billion-second mark falls at 31 years, 251 days: a genuinely arbitrary milestone that has the advantage of being precise, unlike a birthday, which quietly ignores the six hours a year that make leap days necessary. Worth knowing that this counts elapsed days times 86,400 and does not account for leap seconds; there have been 27 of them since 1972, so a strict count of SI seconds since your birth is 27 higher than any calendar-based figure.
Questions
At 31 years and 251 days — about 31 years and eight months.
About 31,557,600 using the 365.25-day Julian year. A common year is 31,536,000.
No, and neither does any calendar. There have been 27 since 1972, so a strict SI count would be that much higher.
It does not; it recalculates from the dates you give it. For a live count you would need a running clock.
Your device’s. The calculation runs in your browser, so it is today where you are rather than on a server somewhere else.