HourToLocation.cs

void Main()
{
  PointF center = new PointF(0f,0f);
  for (int i = 1; i <= 12; i++)
  {
    PointF p = HourToLocation(i, center, 1f);
    Console.WriteLine("{0}\t{1}\t{2:F3},{3:F3}", i, HourToAngle(i), Math.Round(p.X,3), Math.Round(p.Y,3));
  }
}

int HourToAngle(int hour)
{
  if(hour < 1 || hour > 12) throw new ArgumentOutOfRangeException("hour", "Hour must be between 1 and 12");
  
  if (hour <= 3)
    return ((3 - hour) * 30);
  else
    return ((12 - hour) * 30) + 90;
}

PointF HourToLocation(int hour, PointF center, float distance)
{
  double degToRad = Math.PI / 180f;
  int degrees = HourToAngle(hour);
  float x = (float)Math.Cos(degrees * degToRad) * distance;
  float y = (float)Math.Sin(degrees * degToRad) * distance;
  return new PointF(center.X + x, center.Y + y);
}