second () gives back the timerange representing the
first or nth Second of the called object.
Note that seconds normally starts to count at zero,
so ->second(2) gives the third second within
the range.
seconds () give back an array of all the seconds
containing the time periods called. With arguments,
it will give back a range of those seconds, in the
same enumeration as the n to second ().
number_of_seconds () simple counts the
number of seconds containing the called time period.