using System;
class WeekdayCalculatorBetweenTwoDates
{
static void Main()
{
Console.WriteLine(countWeekDays(new DateTime(2025, 1, 1), new DateTime(2025, 1, 7)));
Console.WriteLine(countWeekDays(new DateTime(2025, 2, 1), new DateTime(2025, 2, 10)));
Console.WriteLine(countWeekDays(new DateTime(2024, 1, 1), new DateTime(2024, 12, 31)));
Console.WriteLine(countWeekDays(new DateTime(2025, 1, 1), new DateTime(2025, 12, 31)));
}
public static int countWeekDays(DateTime d1, DateTime d2) {
int ndays = 1 + Convert.ToInt32((d2 - d1).TotalDays);
int nsaturdays = (ndays + Convert.ToInt32(d1.DayOfWeek)) / 7;
return ndays - 2 * nsaturdays
- (d1.DayOfWeek == DayOfWeek.Sunday ? 1 : 0)
+ (d2.DayOfWeek == DayOfWeek.Saturday ? 1 : 0);
}
}
/*
run:
5
6
262
261
*/
