Need combination chart axis help

[vangogh228]

I have built a Gantt chart in excel that allows the entry of start and end dates for tasks (up to 18) and a percent completion. I want to be able to autoscale the time axis based on the minimum and maximum dates of the tasks. Can the scale min and max be calculated from a cell, so that it does not have to be edited manually?

See the file for more info. Some of my data is behind the chart.

Any help is GREATLY appreciated.