GANTTCHART draws a construction programme as a bar chart: a task name column down the left, twelve months across the top, and a coloured bar per task spanning from its start date to its finish.
What GanttChart does
It is drawn as ordinary AutoCAD geometry, so it plots as part of the drawing set and lives on the sheet with everything else — which is the whole point of doing it here rather than in a scheduling package.
The year can start anywhere. Pick the month the programme starts in and the twelve columns rotate to begin there, so a job running August to July reads left to right without wrapping.
How to use it
- Load the routine with
APPLOAD, or put it on your support file search path. - Type
GANTTCHART. - Pick the insertion point and the month the programme starts in.
- Say whether it is a leap year — the scale adjusts.
- Give each task its name, start and finish.
How it works
The twelve columns are not equal width. Each month is as wide as its own number of days, so the horizontal scale is genuinely linear in time.
That means a bar drawn from 20 March to 10 April is the right length, and measuring across the chart gives real durations. Equal-width months — which is what most hand-drawn charts use — quietly distort every bar that crosses a month boundary, and the distortion compounds across a year.
February takes 28 or 29 days depending on whether you say it is a leap year, and the whole scale adjusts with it.
Notes and limits
- Months are scaled by real length, so you can measure durations off the chart.
- Twelve months. A longer programme needs a second chart, or the columns rescaling.
- Set the leap year correctly — it shifts every column after February.
- One undo group covers the chart.
Download and details
| Name | GanttChart — a twelve month programme bar chart, as drawing geometry |
| Download | GanttChart.lsp — 14.6 KB, plain AutoLISP source. Downloads directly; no zip to unpack. |
| Type | AutoCAD AutoLISP routine |
| Command | GANTTCHART |
| Requires | nothing beyond a CAD platform with AutoLISP. |
| Source size | 14.6 KB, 334 lines |
| Error handling | Yes — a *error* handler restores every system variable it changed, on cancel as well as on error. |
| Undo | The whole operation is wrapped in a single undo group, so one U reverses all of it. |
| Compatibility | AutoCAD (any release with AutoLISP), BricsCAD, ZWCAD, GstarCAD, ProgeCAD and other IntelliCAD-based platforms. AutoCAD LT needs a LISP enabler. No .NET, no ObjectARX, no installer. |
| Author | YZ, August 2026 |
| Licence | Free to use, supplied “as is” with no warranty. |
References
- GRAPHGRID LISP — ruled and numbered graph paper for other plots
- TIMELOG LISP — recording the time the work actually took
- More free AutoLISP routines on this site
- Wisey’s Steel Shapes — free structural steel section drawing program