Creating a Gantt chart
Although Excel doesn't support Gantt charts per se, creating a simple Gantt chart is fairly easy. The key is getting your data set up properly.
For example, a Gantt chart set up to depict the schedule for a project, in range A2:C10:

The horizontal axis represents the total time span of the project, and each bar represents a project task. The viewer can quickly see the duration for each task and identify overlapping tasks.
Column A contains the task name, column B contains the corresponding start date, and column C contains the duration of the task, in days.
Follow these steps to create this chart:
1. Use the Chart Wizard to create a stacked bar chart from the range A2:C10.
2. In Step 2 of the Chart Wizard, select the Columns option. Notice that Excel incorrectly uses the first two columns as the Category axis labels.
3. Also in Step 2 of the Chart Wizard, click the Series tab and add a new data series. Then set the chart's series to the following:

- Series 1: B4:B10
- Series 2: C4:C10
- Category (x) Axis Labels: A4:A10
4. In Step 3 of the Chart Wizard, remove the Legend and then click Finish to create an embedded chart.
5. Adjust the height of the chart so that all the axis labels are visible. You can also accomplish this by using a smaller font size for the category axis labels.
6. Double-click the value axis to access the Format Axis dialog box for the value (horizontal) axis. Adjust the horizontal axis Minimum and Maximum scale values to correspond to the earliest and latest dates in the data, (Note that you can enter a date into the Minimum or Maximum box.) You also may want to set the Major unit to 7 to indicate weeks.

7. Access the Format Axis dialog box for the category (vertical) axis. In the Scale tab, select the option labeled Categories in Reverse Order, and also set the option labeled Value (Y) Axis Crosses at Maximum category.

8. Double-click the first data series to access the Format Data Series dialog box.

On the Patterns tab, set Border to None and Area to None. This makes the first data series invisible.
9. Apply other formatting as desired.