Considering Date Versus Text-Based Axes in Excel 2007:-


In most Excel charts, the points along the horizontal axis are equidistant. This makes sense when you are comparing departments or regions or even when you are comparing months of the year.

Other times, your horizontal axis might be based on dates, and these points may not be equally spaced. Figure (given below) shows the results of random quality control audits. Because the audits are supposed to be a surprise, they do not happen at regular periods. In the top chart, the axis uses a text-based setting and shows the points at equal distances from each other. In the bottom chart, the axis uses a date-based setting, and you can see that certain audits happened closer to or farther away from each other.

Excel often auto-selects which type of axis to use. To control the axis setting, you can select Layout, Axes, Primary Horizontal Axis, More Primary Horizontal Axis Options, Axis Options, and choose Text Axis or Date Axis from the Axis Type section.



(You can explicitly control whether the horizontal axis is equally spaced, as in the text-based axis here, or if it is date based.)