DateTime Label Every Second

Hi, I do not quite understand how the datetimeaxis works and I can not find any documentation, I've been playing with the IntervalType, IntervalLength , MajorStep properties and I quite do not understand how is it working, I want a label every second.

        PlotModel.Axes.Add(new OxyPlot.Axes.DateTimeAxis()
        {
            Position = AxisPosition.Bottom, 
            IsPanEnabled = false,
            IsZoomEnabled = false,
            StringFormat = "mm:ss",
            IntervalType = DateTimeIntervalType.Seconds?,
            IntervalLength = ??,,
            MajorStep = ??,
        });