LEAPYEAR
if ((month > 2) && LEAPYEAR(year))
days += DAYSPERYEAR + LEAPYEAR(y);
for (y = 1970, m = DAYSPERYEAR + LEAPYEAR(y);
y++, m = DAYSPERYEAR + LEAPYEAR(y))
if (m == 1 && LEAPYEAR(y))