DateTime puvodnicas = DateTime.Now;
Console.WriteLine(puvodnicas);

Thread.Sleep(1000);
DateTime novejsicas = DateTime.Now;
Console.WriteLine(novejsicas);

TimeSpan duration = novejsicas - puvodnicas;
duration = TimeSpan.FromTicks(duration.Ticks * 60);
Console.WriteLine(duration);

DateTime hernicas = puvodnicas + duration;

Console.WriteLine(hernicas);