You can make a copy of the Gantt Chart worksheet within the same workbook and rename the worksheets GanttChart-Actual and GanttChart-Plan(see the image below). Of course, t… See more

It's easy to insert new columns in the XLSX version of the Gantt chart. Many people do that to add a budget column, and in this case you could add columns to keep track of original s… See more

The first two approaches don't make it easy to visually compare differences between the planned and actual dates. The third method gets us part way there, but many people have wante… See more

Update 3/19/2019: Although cross-hatching isn't currently possible as a conditional formatting option in Google Sheets (or Excel Online), I figured out how to implement i… See more