Year
In astronomy, the Julian year is a unit of time; it is defined as 365.25 days of exactly 86,400 seconds (SI base unit), totalling exactly 31,557,600 seconds in the Julian astronomical year.
Thomas Fuller (mental calculator)
First, when they asked him how many seconds there were in a year and a half, he answered in about two minutes, 47,304,000. Second, when they asked how many seconds a man has lived who is 70 years, 17 days and 12 hours old, he answered in a minute and a half 2,210,500,800. One of the men was working out the problems on paper, and informed Fuller that he was wrong, because the answer was much smaller. Fuller hastily replied, "'Top, massa, you forget de leap year." When the leap year was added in, the sums matched.