public static DateD operator +(DateD d, int days)
{
int daysRemain = Math.Abs(days);
DateD result = new DateD(d.Year, d.Month, d.Day);
while (daysRemain > 0)
{
if (days > 0)
{
int count = DaysInMonth(result.Month, result.Year) - result.Day;
if (daysRemain > count)
{
daysRemain -= count + 1;
result.Month++;
result.Day = 1;
if (result.Month > 12)
{
result.Year++;
result.Month = 1;
}
}
else
{
result.Day += daysRemain;
break;
}
}
else
{
int count = result.Day;
if (daysRemain >= count)
{
daysRemain -= count;
result.Month--;
result.Day = DaysInMonth(result.Month, result.Year);
if (result.Month < 1)
{
result.Year--;
result.Month = 12;
}
}
else
{
result.Day -= daysRemain;
break;
}
}
}
return(result);
}
public static int operator -(DateD d1, DateD d2)
{
DateD dateMin = d1 < d2 ? d1 : d2;
DateD dateMax = d1 > d2 ? d1 : d2;
int monthTmp = dateMin.Month;
int YearTmp = dateMin.Year;
int res = dateMax.Day - dateMin.Day;
while (monthTmp != dateMax.Month || YearTmp != dateMax.Year)
{
res += DaysInMonth(monthTmp, YearTmp);
monthTmp++;
if (monthTmp > 12)
{
monthTmp = 1;
YearTmp++;
}
}
return(d1 > d2 ? res : -res);
}
