
A timeline, or chronological chart, in PowerPoint serves to illustrate a journey over time. This guide by PresentationSkills101.com will walk you through creating professional-grade time milestones in PowerPoint.
PowerPoint allows users to create a basic timeline and freely adjust manual arrangements to fit data and user needs. Its output is a simple graphic format suitable for presentations, but lacks flexibility if you want to display more precise details and update timelines frequently.
Here, PresentationSkills101.com will guide you on how to create a simple manual timeline.
Firstly, create a new blank slide.

Click on the Insert ribbon on the toolbar and select SmartArt in the Illustrations group.

The Choose a SmartArt Graphic function window appears, click on the Process tab. Here, you can freely choose the PowerPoint timeline graphic you want. Choose Basic Timeline to describe the timeline graph in the simplest way.
Click OK to confirm insertion.

After Basic Timeline is inserted into your slide, you can add data to it by clicking on [Text] and typing in your text.

To add additional milestones, you can do so in Type your text here. Click on the information line just before the position where you want to insert and then press Enter to create a new milestone.
To create a line break for information (like breaking dates in the image below), use the Ctrl Enter key combination.

You can also manually customize by dragging to move milestone columns to better fit time intervals.

Congratulations on completing the timeline creation process in PowerPoint. Now, all that's left is to enhance your timeline's appearance.
To customize the overall interface of your timeline, you can change its colors and styles by clicking on the timeline, then opening the Design ribbon in SMARTART TOOLS (appears when you click on the timeline).
Choose different layouts at Layouts and accompanying colors at SmartArt Styles.
Alternatively, you can also change the color scheme at Change Colors.

If you prefer not to choose from the available color combinations suggested by PowerPoint, you can customize individual color schemes for each component of the timeline by clicking on each timeline element and changing its color.