isBusinessDay method
Checks if this date is a business day.
A business day is one that is not a weekend and not a holiday.
Implementation
bool isBusinessDay([BusinessDayConfig config = BusinessDayConfig.standard]) {
if (!isValid) return false;
// Check if weekend
if (config.weekendDays.contains(weekday)) {
return false;
}
// Check if holiday
if (config.holidays.isHoliday(dateTime)) {
return false;
}
return true;
}