is_leap_year
if (is_leap_year(year) && month > FEBRUARY)
if (is_leap_year(yr) && mon > 2)
if (is_leap_year(yr) && mon > 2)
if (is_leap_year(yr) && mon > 2)
if (is_leap_year(y) && mon > 2)
if (i == 1 && is_leap_year(dt->dt_year))
if (is_leap_year(year) && dt->dt_mon > FEBRUARY)
return is_leap_year(year) ? DAYS_PER_LEAP_YEAR : DAYS_PER_COMMON_YEAR;