Axis.MajorUnitScale (PowerPoint)

Returns or sets the major unit scale value for the category axis when the CategoryType property is set to xlTimeScale.

Possible Values are xlDays - Days, xlMonths - Months, xlYears - Years.

MajorUnitScale can be one of the following xlTimeUnit constants:

ActivePresentation.Slides(1).Shapes(1).Chart.Axes(1).MajorUnitScale = xlDays