Gantt Charts

A Gantt chart is a plan on a calendar. It starts with gantt and its title.

gantt Launching the site
start: 2026-11-02
skip: weekends
today: 2026-11-12
section Design
Sketches: 3d [done]
Mock-ups: after Sketches, 4d [done]
section Build
Pages: after Mock-ups, 6d [active]
Search: after Mock-ups, 4d
Testing: after Pages and Search, 3d [critical]
section Ship
Launch: after Testing, milestone

The text above: tasks in three sections on a calendar, weekends shaded, a dashed line on the twelfth, lines from each task to the tasks waiting for it, and a diamond for the launch

Settings

Setting	Also	Value
`start`	`starts`, `begin`, `from`	the date a task starts on when nothing else says
`today`	`now`, `status date`	a day marked with a line
`skip`	`excludes`, `exclude`, `holidays`	`weekends`, and dates not worked, apart by commas: `skip: weekends, 2026-12-25`
`dates`	`date format`, `axis format`, `format`	how the calendar writes its dates, in the D3 time format: `%b %d` for Nov 02, `%d/%m` for 02/11

Tasks

Each line is a task: its name, a colon, then when it starts and how long it takes, apart by commas.

Part	Means
`3d`, `1w`, `4h`, `1d 4h`	how long it takes, in days, weeks, hours or minutes
`2026-11-02`, `from 2026-11-02`, `on 2026-11-02`	the day it starts
`after Pages`, `after Pages and Search`, `after Pages, Search`	it starts when every task named has ended
`until 2026-11-20`, `to …`, `end …`, or a second date	the day it ends, that day included
`milestone`	a moment rather than a stretch of time, drawn as a diamond

A task with no start starts when the task above it ends, or on the chart's start; one with no length takes a day. A task's name after after is matched ignoring case. Skipped days are not counted in a length, and no task starts on one.

A task's state

Words in brackets after the name or after the timing say how a task stands:

Word	Also	Drawn
`done`	`complete`, `completed`, `finished`	greyed
`active`	`current`, `now`, `in progress`, `doing`	filled
`critical`	`crit`, `urgent`	outlined in red
`milestone`		a diamond

A colour in brackets colours a task.

Sections

section Name labels the tasks after it, and its band runs across the calendar behind them.

Problems a plan can have

A task that waits for a task the chart has not got is said, with the name it was given.
A task with no date to start from - no date of its own, nothing above it, no start - is said.
Tasks that wait for each other in a circle are said; give one of them a date to start on.
A task that ends before it starts, or a name used for two tasks, is said.

Problems has the words of each.