How many seconds are there in a leap year with leap seconds?

1 day = 86,400 seconds 1 leap year = 366 days = 366 times 86,400 = 31,622,400 seconds. The number of leap seconds added is a decision by the worldwide community of scientists. In any given year, there may be some leap seconds added, or there may be none. If any leap seconds are added to a leap year, the total is the number above PLUS the number of leap seconds.