Numbers is Apple's version of Spreadsheet software available on the Mac which can be used to create a Gantt chart in a similar way to other online and desktop spreadsheet software.
The basis for the Gantt Chart in Apple Numbers is to use a stacked bar chart format with two data sets. Firstly the days from the start of the project to the start of the task, and then the days required to complete the task. By changing the colour of the first part of the stacked bar then the result looks like the usual task bar in a Gantt Chart. Nice tip!
Open Numbers and create a new spreadsheet using the Blank template.
Step 1 - Start the table
Create the table by adding column headers for Tasks, Days to Start & Duration. Format the headers as required, font type, bold etc. Ensure the Task column is in the first column of the table as it will become the row labels automatically.
Step 2 - Add the task data to the table
Add the task details, when they are planned to start in days from the beginning of the project, and the expected duration in days. These values can be adjusted later as needed, and even values (tasks) inserted between others or added on.
Step 3 - Select all of the table created
Drag over the cells to highlight everything from the headers to the end of the data.
Step 4 - Insert a Stacked Bar Chart
To insert a chart either use the Chart icon in the very top row selecting the Stacked Bar chart type from the drop down list of chart types, or use the main menu item Insert, then select Chart and 2D Stacked Bar.
Step 5 - Format the bars
On the chart click one of the Days to Start bars (in blue) which will select the whole series.
In the right hand side toolbar select the Style tab and select No Fill from the Fill dropdown menu. This will make the blue colour disappear leaving just the Duration element of the bar as in a Gantt Chart.
In the same way the duration bars, which are now the Gantt Chart tasks, can be formatted to a suitable colour.
The Gantt Chart can be further customised as needed by removing or changing the titles, or adjusting the colours etc using the right sidebar options.