//引入命名空间
using System;

public class DateArithmetic
{
   public static void Main()
   {
      DateTime date1, date2;
      DateTimeOffset dateOffset1, dateOffset2;
      TimeSpan difference;
      
      // Find difference between Date.Now and Date.UtcNow
      date1 = DateTime.Now;
      date2 = DateTime.UtcNow;
      difference = date1 - date2;
      Console.WriteLine("{0} - {1} = {2}", date1, date2, difference);
      
      // Find difference between Now and UtcNow using DateTimeOffset
      dateOffset1 = DateTimeOffset.Now;
      dateOffset2 = DateTimeOffset.UtcNow;
      difference = dateOffset1 - dateOffset2;
      Console.WriteLine("{0} - {1} = {2}", 
                        dateOffset1, dateOffset2, difference);
      // If run in the Pacific Standard time zone on 4/2/2007, the example
      // displays the following output to the console:
      //    4/2/2007 7:23:57 PM - 4/3/2007 2:23:57 AM = -07:00:00
      //    4/2/2007 7:23:57 PM -07:00 - 4/3/2007 2:23:57 AM +00:00 = 00:00:00                        
   }
}