Gantt chart maker

The chart is named after Henry Gantt, who devised it with Frederick Taylor around the turn of the twentieth century as a way of describing production planning and resource loading in a factory; the first ones were closer to tables than to charts. The form was used to plan the Hoover Dam and the American interstate system, on paper, with the bars redrawn by hand every time anything moved, which explains a great deal about why project plans of that era changed so rarely.

Both ends of a task are inclusive here, so a task from the 5th to the 5th is one day rather than zero. That sounds pedantic and is not: a zero-length bar is invisible, and single-day tasks. A launch, a review, a handover: are among the most common things anyone puts on a chart.

What this deliberately does not model is dependencies. A real Gantt chart draws arrows between tasks that cannot start until another finishes, and that is where the value is in serious project management: it is what lets software recalculate everything downstream when one task slips. Adding it means a dependency graph, cycle detection and automatic rescheduling, which is a different product. This draws what you tell it.

So it is right for a plan you want to show someone; a proposal, a status update, a wall, and wrong as a planning tool for anything with real interdependencies. For that you want software that recalculates.

The output is landscape because a timeline needs width far more than height, and vector so it stays sharp printed at A3 for a wall.