Gantt Diagram

The Gantt is described in natural language, using very simple sentences (subject-verb-complement).

Declaring tasks

Tasks defined using square bracket.

Duration

Their durations are defined using the last verb:

@startgantt
[Prototype design] lasts 15 days
[Test prototype] lasts 10 days
@endgantt

Start

Their beginning are defined using the start verb:

@startuml
[Prototype design] lasts 15 days
[Test prototype] lasts 10 days

Project starts 2020-07-01
[Prototype design] starts 2020-07-01
[Test prototype] starts 2020-07-16
@enduml

End

Their ending are defined using the end verb:

@startuml
[Prototype design] lasts 15 days
[Test prototype] lasts 10 days

Project starts 2020-07-01
[Prototype design] ends 2020-07-15
[Test prototype] ends 2020-07-25

@enduml

Start/End

It is possible to define both absolutely, by specifying dates:

@startuml

Project starts 2020-07-01
[Prototype design] starts 2020-07-01
[Test prototype] starts 2020-07-16
[Prototype design] ends 2020-07-15
[Test prototype] ends 2020-07-25

@enduml

One-line declaration (with the and conjunction)

It is possible to combine declaration on one line with the and conjunction.

@startuml
Project starts 2020-07-01
[Prototype design] starts 2020-07-01 and ends 2020-07-15
[Test prototype] starts 2020-07-16 and lasts 10 days
@enduml

Adding constraints

It is possible to add constraints between tasks.

@startgantt
[Prototype design] lasts 15 days
[Test prototype] lasts 10 days
[Test prototype] starts at [Prototype design]'s end
@endgantt

@startgantt
[Prototype design] lasts 10 days
[Code prototype] lasts 10 days
[Write tests] lasts 5 days
[Code prototype] starts at [Prototype design]'s end
[Write tests] starts at [Code prototype]'s start
@endgantt

Short names

It is possible to define short name for tasks with the as keyword.

@startgantt
[Prototype design] as [D] lasts 15 days
[Test prototype] as [T] lasts 10 days
[T] starts at [D]'s end
@endgantt

Customize colors

It is also possible to customize colors with is colored in.

@startgantt
[Prototype design] lasts 13 days
[Test prototype] lasts 4 days
[Test prototype] starts at [Prototype design]'s end
[Prototype design] is colored in Fuchsia/FireBrick
[Test prototype] is colored in GreenYellow/Green
@endgantt

Completion status

You can set the completion status of a task.

@startgantt
[foo] lasts 21 days
[foo] is 40% completed
[bar] lasts 30 days and is 10% complete
@endgantt

Milestone

You can define Milestones using the happens verb.

@startuml
[Themenfindung] lasts 10 days
[Themenfindung] is colored in CornflowerBlue
[Anforderungsanalyse] lasts 10 days
[Beginn Projektplanung] lasts 10 days
[Beginn Projektplanung] starts at [Anforderungsanalyse]'s end
[Aufgaben verteilen] happens at [Beginn Projektplanung]'s end
[Setup assembly line] lasts 12 days
[Setup assembly line] starts at [Beginn Projektplanung]'s end
@enduml

Hyperlinks

You can add hyperlinks to tasks.

@startgantt
[task1] lasts 10 days
[task1] links to [[http://plantuml.com]]
@endgantt

Calendar

You can specify a starting date for the whole project. By default, the first task starts at this date.

@startgantt
Project starts the 20th of september 2017
[Prototype design] as [TASK1] lasts 13 days
[TASK1] is colored in Lavender/LightBlue
@endgantt

Coloring days

It is possible to add colors to some days.

@startgantt
Project starts the 2020/09/01 

2020/09/07 is colored in salmon
2020/09/13 to 2020/09/16 are colored in lightblue

[Prototype design] as [TASK1] lasts 22 days
[TASK1] is colored in Lavender/LightBlue
[Prototype completed] happens at [TASK1]'s end
@endgantt

Changing scale

You can change scale for very long project, with one of those parameters:

printscale
ganttscale
projectscale

and one of the values:

daily (by default)
weekly
monthly

(See QA-11272, QA-9041 and QA-10948)

@startgantt
printscale weekly
Project starts the 20th of september 2020
[Prototype design] as [TASK1] lasts 130 days
[TASK1] is colored in Lavender/LightBlue
[Testing] lasts 20 days
[TASK1]->[Testing]
@endgantt

@startgantt
projectscale monthly
Project starts the 20th of september 2020
[Prototype design] as [TASK1] lasts 130 days
[TASK1] is colored in Lavender/LightBlue
[Testing] lasts 20 days
[TASK1]->[Testing]
@endgantt

Close day

It is possible to close some day.

@startgantt
project starts the 2018/04/09
saturday are closed
sunday are closed
2018/05/01 is closed
2018/04/17 to 2018/04/19 is closed
[Prototype design] lasts 14 days
[Test prototype] lasts 4 days
[Test prototype] starts at [Prototype design]'s end
[Prototype design] is colored in Fuchsia/FireBrick
[Test prototype] is colored in GreenYellow/Green
@endgantt

Then it is possible to open some closed day.

@startgantt
2020-07-07 to 2020-07-17 is closed
2020-07-13 is open

Project starts the 2020-07-01
[Prototype design] lasts 10 days
Then [Test prototype] lasts 10 days
@endgantt

Simplified task succession

It's possible to use the then keyword to denote consecutive tasks.

@startgantt
[Prototype design] lasts 14 days
then [Test prototype] lasts 4 days
then [Deploy prototype] lasts 6 days
@endgantt

You can also use arrow ->

@startgantt
[Prototype design] lasts 14 days
[Build prototype] lasts 4 days
[Prepare test] lasts 6 days
[Prototype design] -> [Build prototype]
[Prototype design] -> [Prepare test]
@endgantt

Separator

You can use -- to separate sets of tasks.

@startgantt
[Task1] lasts 10 days
then [Task2] lasts 4 days
-- Phase Two --
then [Task3] lasts 5 days
then [Task4] lasts 6 days
@endgantt

Working with resources

You can affect tasks on resources using the on keyword and brackets for resource name.

@startgantt
[Task1] on {Alice} lasts 10 days
[Task2] on {Bob:50%} lasts 2 days
then [Task3] on {Alice:25%} lasts 1 days
@endgantt

Multiple resources can be assigned to a task:

@startgantt
[Task1] on {Alice} {Bob} lasts 20 days
@endgantt

Resources can be marked as off on specific days:

@startgantt
project starts on 2020-06-19
[Task1] on {Alice} lasts 10 days
{Alice} is off on 2020-06-24 to 2020-06-26
@endgantt

Complex example

It also possible to use the and conjunction.

You can also add delays in constraints.

@startgantt
[Prototype design] lasts 13 days and is colored in Lavender/LightBlue
[Test prototype] lasts 9 days and is colored in Coral/Green and starts 3 days after [Prototype design]'s end
[Write tests] lasts 5 days and ends at [Prototype design]'s end
[Hire tests writers] lasts 6 days and ends at [Write tests]'s start
[Init and write tests report] is colored in Coral/Green
[Init and write tests report] starts 1 day before [Test prototype]'s start and ends at [Test prototype]'s end
@endgantt

Comments

As is mentioned on Common Commands page:

Everything that starts with simple quote ' is a comment.
You can also put comments on several lines using /' to start and '/ to end.

(i.e.: the first character (except space character) of a comment line must be a simple quote ')

@startgantt
' This is a comment

[T1] lasts 3 days

/' this comment
is on several lines '/

[T2] starts at [T1]'s end and lasts 1 day
@endgantt

Using style

@startuml
<style>
ganttDiagram {
	task {
		FontName Helvetica
		FontColor red
		FontSize 18
		FontStyle bold
		BackGroundColor GreenYellow
		LineColor blue
	}
	milestone {
		FontColor blue
		FontSize 25
		FontStyle italic
		BackGroundColor yellow
		LineColor red
	}
	note {
		FontColor DarkGreen
		FontSize 10
		LineColor OrangeRed
	}
}
</style>
[Task1] lasts 20 days
note bottom
  memo1 ...
  memo2 ...
  explanations1 ...
  explanations2 ...
end note
[Task2] lasts 4 days
[Task1] -> [Task2]
-- Separator title --
[M1] happens on 5 days after [Task1]'s end
-- end --
@enduml

Add notes

@startgantt
[task01] lasts 15 days
note bottom
  memo1 ...
  memo2 ...
  explanations1 ...
  explanations2 ...
end note

[task01] -> [task02]

@endgantt

Example with overlap.

@startgantt
[task01] lasts 15 days
note bottom
  memo1 ...
  memo2 ...
  explanations1 ...
  explanations2 ...
end note

[task01] -> [task02]
[task03] lasts 5 days

@endgantt

@startgantt

-- test01 --

[task01] lasts 4 days
note bottom
'note left
memo1 ...
memo2 ...
explanations1 ...
explanations2 ...
end note

[task02] lasts 8 days
[task01] -> [task02]
note bottom
'note left
memo1 ...
memo2 ...
explanations1 ...
explanations2 ...
end note
-- test02 --

[task03] as [t3] lasts 7 days
[t3] -> [t4]
@endgantt

DONE

Thanks for correction (of #386 on v1.2020.18) when overlapping

@startgantt

Project starts 2020-09-01

[taskA] starts 2020-09-01 and lasts 3 days
[taskB] starts 2020-09-10 and lasts 3 days
[taskB] displays on same row as [taskA]

[task01] starts 2020-09-05 and lasts 4 days

then [task02] lasts 8 days
note bottom
  note for task02
  more notes
end note

then [task03] lasts 7 days
note bottom
  note for task03
  more notes
end note

-- separator --

[taskC] starts 2020-09-02 and lasts 5 days
[taskD] starts 2020-09-09 and lasts 5 days
[taskD] displays on same row as [taskC]

[task 10] starts 2020-09-05 and lasts 5 days
then [task 11] lasts 5 days
note bottom
  note for task11
  more notes
end note
@endgantt

Pause tasks

@startgantt
Project starts the 5th of december 2018
saturday are closed
sunday are closed
2018/12/29 is opened
[Prototype design] lasts 17 days
[Prototype design] pauses on 2018/12/13
[Prototype design] pauses on 2018/12/14
[Prototype design] pauses on monday
[Test prototype] starts at [Prototype design]'s end and lasts 2 weeks
@endgantt

Change link colors

@startgantt
[T1] lasts 4 days
[T2] lasts 4 days and starts 3 days after [T1]'s end with blue dotted link
[T3] lasts 4 days and starts 3 days after [T2]'s end with green bold link
[T4] lasts 4 days and starts 3 days after [T3]'s end with green dashed link
@endgantt

@startuml
Links are colored in blue
[Prototype design] lasts 14 days
[Build prototype] lasts 4 days
[Prepare test] lasts 6 days
[Prototype design] -[#FF00FF]-> [Build prototype]
[Prototype design] -[dotted]-> [Prepare test]
@enduml

Tasks or Milestones on the same line

@startgantt
[Prototype design] lasts 13 days
[Test prototype] lasts 4 days and 1 week
[Test prototype] starts 1 week and 2 days after [Prototype design]'s end
[Test prototype] displays on same row as [Prototype design]
[r1] happens on 5 days after [Prototype design]'s end
[r2] happens on 5 days after [r1]'s end
[r3] happens on 5 days after [r2]'s end
[r2] displays on same row as [r1]
[r3] displays on same row as [r1]
@endgantt

Highlight today

@startgantt
Project starts the 20th of september 2018
sunday are close
2018/09/21 to 2018/09/23 are colored in salmon
2018/09/21 to 2018/09/30 are named [Vacation in the Bahamas] 

today is 30 days after start and is colored in #AAF
[Foo] happens 40 days after start
[Dummy] lasts 10 days and starts 10 days after start

@endgantt

Task between two milestones

@startgantt
project starts on 2020-07-01
[P_start] happens 2020-07-03
[P_end]   happens 2020-07-13
[Prototype design] occurs from [P_start] to [P_end]
@endgantt

Grammar and verbal form

Verbal form	Example
[T] starts
[M] happens

Add title, header, footer, caption or legend on gantt diagram

@startuml

header some header

footer some footer

title My title

[Prototype design] lasts 13 days

legend
The legend
end legend

caption This is caption

@enduml

(See also: Common commands)