leaps_thru_end_of
-(leaps_thru_end_of(-(y + 1)) + 1);
static int __pure leaps_thru_end_of(int y);
leapdays = leaps_thru_end_of(newy - 1) -
leaps_thru_end_of(y - 1);
leaps_thru_end_of(y - 1) -
leaps_thru_end_of(EPOCH_YEAR - 1) +
leaps_thru_end_of(year - 1) -
leaps_thru_end_of(EPOCH_YEAR - 1) +
-(leaps_thru_end_of(-(y + 1)) + 1);
static int leaps_thru_end_of(const int y);