10/19   I know leap years occur every 4 years, but there was some exception
        to that. Can anyone tell me what it was? I believe it involved years
        that were multiples of either 100 or 400. Thanks.
        \_ http://www.boulder.nist.gov/timefreq/general/leaps.htm
        \_ Year mod 4 == 0, leap year
           Year mod 100 == 0, no leap year
           Year mod 400 == 0, leap year
           ... possibly some other wrinkles.
           It basically come from the decimal expansion of the number of days
           in a year.  Of course the length of a day changes too...
           \_ More specifically if ((year%4 == 0 && year%100 !=0) || year%400
              ==0) leapyear = TRUE; else leapyear = FALSE;
              \_ Ergh, don't write
                    if (bool) x = true; else x = false;
                 statements!  Just set x = bool!
        \_ The above is right, and there are no other wrinkles.  Incidentally,
           this calendar was chosen because it was the most accurate system
           they could get the monks (who kept time back in the day) to
           actually memorize without error. -- ilyas
           \_ Every once in a while you'll see a leap second added.
              \_ Ok, that must be a latter addition to the original
                 calendar.  My mistake. -- ilyas