_yconv
pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 0,
static char *_yconv(int, int, int, int, char *, const char *);
pt = _yconv(year, base, 0, 1,
pt = _yconv(year, base, 1, 1,
pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1,
pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1,