How to visualize calendar dates (in Keynote? Or Numbers?)
You might want to try the Office "gantt chart" feature to present your data.


  Options for making a Gantt chart
  
  Although it is not a graphical tool by design, it is possible, with
  quite a bit of formatting, to make a Gantt chart in Excel. You can do
  this by turning your project tables into an Excel Gantt chart using
  Excel's bar graph functionality. It is also possible and significantly
  easier to create much more graphical and more manageable Gantt charts
  in PowerPoint, such as the one above. You can do this by simply
  pasting your Excel project tables into a PowerPoint add-in called
  Office Timeline.


There are many templates available here.