Here is the code I used. You should be able to learn everything you need to know by evaluating it.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace UTC
{
    class Program
    {
        static void Main(string[] args)
        {
            DateTime dt = DateTime.Now;

            Console.WriteLine("Outputting the type of DateTime object used:");

            Console.WriteLine(dt.Kind);

            Console.WriteLine("\nOutputting the current time as is:");

            Console.WriteLine(dt);

            Console.WriteLine("\nOutputting the current time using the ToUniversalTime() function:");

            Console.WriteLine(dt.ToUniversalTime());

            Console.WriteLine("\nOutputting the current time using the ToFileTime() function:");

            Console.WriteLine(dt.ToFileTime());

            Console.WriteLine("\nOutputting the current time using the ToFileTimeUtc() function:");

            Console.WriteLine(dt.ToFileTimeUtc());

            Console.WriteLine("\nOutputting the current time using the Ticks property:");

            Console.WriteLine(dt.ToFileTimeUtc());

            Console.WriteLine("\nCreating a DateTime and setting it as follows:\nDateTime udt1 = DateTime.Parse(\"1/1/1970\");");

            DateTime udt1 = DateTime.Parse("1/1/1970");

            Console.WriteLine(udt1);

            Console.WriteLine("\nCreating a DateTime and setting it as follows:\nnew DateTime(1970, 1, 1, 0, 0, 0, 0);");

            DateTime udt2 = new DateTime(1970, 1, 1, 0, 0, 0, 0);

            Console.WriteLine(udt1);

            Console.WriteLine("\nOutputting the time stamp of this Unix Time Stamp value: 1254322574 (seconds)\nTo do this i use these lines:\n DateTime udt1 = new DateTime(1970, 1, 1, 0, 0, 0, 0);\n udt.AddSeconds(1254322574448);");

            Console.WriteLine(udt1.AddSeconds(1254322574));

            Console.WriteLine("\nOutputting the time stamp of this Unix Time Stamp value: 1254322574789 (milliseconds)\nTo do this i use these lines:\n DateTime udt1 = new DateTime(1970, 1, 1, 0, 0, 0, 0);\n udt.AddMilliseconds(1254322574448);");

            Console.WriteLine(udt1.AddMilliseconds(1254322574789));

        }
    }
}

Ok, so here is the output:

Outputting the type of DateTime object used:
Local

Outputting the current time as is:
9/30/2009 3:49:18 PM

Outputting the current time using the ToUniversalTime() function:
9/30/2009 9:49:18 PM

Outputting the current time using the ToFileTime() function:
128988209584600486

Outputting the current time using the ToFileTimeUtc() function:
128988209584600486

Outputting the current time using the Ticks property:
128988209584600486

Creating a DateTime and setting it as follows:
DateTime udt1 = DateTime.Parse(“1/1/1970”);
1/1/1970 12:00:00 AM

Creating a DateTime and setting it as follows:
new DateTime(1970, 1, 1, 0, 0, 0, 0);
1/1/1970 12:00:00 AM

Outputting the time stamp of this Unix Time Stamp value: 1254322574 (seconds)
To do this i use these lines:
DateTime udt1 = new DateTime(1970, 1, 1, 0, 0, 0, 0);
udt.AddSeconds(1254322574448);
9/30/2009 2:56:14 PM

Outputting the time stamp of this Unix Time Stamp value: 1254322574789 (milliseconds)
To do this i use these lines:
DateTime udt1 = new DateTime(1970, 1, 1, 0, 0, 0, 0);
udt.AddMilliseconds(1254322574448);
9/30/2009 2:56:14 PM
Press any key to continue . . .