using System.Timers;

void Main()
{
    Timer t = new Timer();
    t.Interval = 500; //In milliseconds here
    t.AutoReset = true; //Stops it from repeating
    t.Elapsed += new ElapsedEventHandler(TimerElapsed);
    t.Start();
}

void TimerElapsed(object sender, ElapsedEventArgs e)
{
    Console.WriteLine("Hello, world!");
}

Thread.Sleep(500);

System.Threading.Thread.Sleep(500);

void Main()
{
    System.Threading.Thread check= new System.Threading.Thread(CheckMethod);
    check.Start();
}

private void CheckMethod()
{
     //Code
     Thread.Sleep(500);
}