Why python time has 61 seconds

Question

Did anybody notice that the interval of second in Python datetime is [00,61] see the table in the bottom of this page. http://docs.python.org/library/datetime.html#strftime-

Answer 1

There is no such thing as a double leap second. There cannot be 62 seconds in a minute. 59, yes. 60, yes. 61, yes. 62, no.

http://www.monkey.org/openbsd/archive2/tech/199905/msg00031.html