Creating data visualization graphics has always fascinated me so I wanted to figure out how it was done. And I did! So here is how I made my data-vis connector graphic in Illustrator. Looks complicated but it was less complicated than I thought.
Start with setting up a grid structure to snap the points of the the lines to. Under Illustrator Preferences choose Guides & Grid.
Set the Gridline to be 10 pt, 10 mm or 10 px. The set the subdivision to be 10. This will give you a point to snap to at every 10 intervals and grid lines at every 1 unit intervals.
Turn the Grid on under the View menu>Show Grid. Then turn on the Snap to Grid under the same menu.
Using the grid structure, set connector points for starting the connector lines. I used every 30 units for spacing.
Duplicate the points every 30 units. Then use COMMAND + D to duplicate several more points.
Duplicate the dots to the lower section of the chart. Keep them inline with the upper dots. Select all the dots and lock them. Object> Lock> Selection.
Using the dot as reference, draw a connector line 10 units below the dot (snapped to the grid) then connect it to the lower dot, 10 units above the dot.
Use the pen tool to draw the line from connector to connector.
Copy the line, then choose Edit>Paste in Front. Use the Selection Tool to transform the copied line to meet the next connector.
Repeat this process to match the points on the grid lining up with the lower point.
Change the line colors as you add connector groups.
Using curved line will be easier to follow instead of straight lines.
Use contrasting colors to differentiate between the connector lines.
To change the width of the connector lines, use the Width Shape Tool to widen the ends of the line.
Widen the lines to meet the ends or to cover more area. Final data visualization graphic with days and dates in place.
To create a more easy to follow chart, set the wider lines to 50% opacity.