Gets or sets the base unit for the date axis.
An AxisTimeUnits enumeration value specifying the base time unit.
The base unit is a fundamental unit that specifies how to plot data along the date axis: in days, months, or years. By default, the BaseTimeUnit property is set to AxisTimeUnits.Auto, so the base unit is evaluated automatically based on the smallest difference between any two dates in a worksheet.
You can also specify the time unit for major and minor tick marks on the axis by utilizing the Axis.MajorTimeUnit and Axis.MinorTimeUnit properties. To set the distance between these tick marks, use the Axis.MajorUnit and Axis.MinorUnit properties.