Seconds from 19xx to Date (leap seconds)

[Bob Devine]

Stephen Friedl asked:
>"Doug, why does a time_t range from 0 through 61?"
 
Doug Gwyn replied:
> The answer is, there was one magic moment in history when TWO leap
> seconds were added to the same minute.

  No, there is not a minute that contains two leap seconds.  However
the year 1972 contains one at the end of June and another at the
end of December.  Yep, leap seconds are ugly!

  So the range of 0-60 is sufficient with 0-59 being the usual values.

Bob Devine