Phases, dates, and dependencies
A Gantt chart shows phases on a calendar, with start dates, end dates, and dependencies between tasks. Use it when the reader must see what blocks what.
A timeline is the neighbor for events in order, grouped into periods, without task bars or dependency arrows. If you have no dates and no waiting relationships, use a timeline instead.
Gantt or timeline
Choose a Gantt chart for a plan with owners, durations, and tasks that cannot start until another finishes. Choose a timeline for a history or a launch narrative where the order of events matters more than the schedule logic.
Make the schedule believable
1. Put a date on every bar
Give each task a start and an end, or a start and a duration. Undated bars are the first fix after the draft.
2. State the dependency in words
Say that testing starts after build finishes. Then check the draft arrow. If it points the wrong way, reverse it.
3. Cut tasks that are really milestones
A single date with no length can stay as a milestone. A list of historical events belongs on a timeline.
How to phrase the prompt
Group tasks into phases. For each task, give the name, the start, the end, and the task it waits on. Mention a date format once, such as 2026-04-01. Skip status columns. Those belong on a kanban board.
Schedule draft questions
- What if I only know week numbers?
- Use weeks in the prompt and keep one numbering style. Mixed weeks and calendar dates make the bars overlap for the wrong reason.
- The bars all start on the same day. Why?
- The prompt listed tasks but not dependencies. Add the waiting links and generate again.
- Can I show a person assigned to each task?
- Put the owner in the task name if the team needs it. The chart still has to show dates and dependencies, or a timeline is enough.