# Gantt diagrams **Edit this Page** [![N|Solid](./img/GitHub-Mark-32px.png)](./gantt.md) > A Gantt chart is a type of bar chart, first developed by Karol Adamiecki in 1896, and independently by Henry Gantt in the 1910s, that illustrates a project schedule and the amount of time it would take for any one project to finish. Gantt charts illustrate number of days between the start and finish dates of the terminal elements and summary elements of a project. ## A note to users Gantt Charts will record each scheduled task as one continuous bar that extends from the left to the right. The x axis represents time and the y records the different tasks and the order in which they are to be completed. It is important to remember that when a date, day, or collection of dates specific to a task are "excluded", the Gantt Chart will accomodate those changes by extending an equal number of day, towards the right, not by creating a gap inside the task. As shown here ![](https://raw.githubusercontent.com/NeilCuzon/mermaid/develop/docs/img/Gantt-excluded-days-within.png) However, if the excluded dates are between two tasks that are set to start consecutively, the excluded dates will be skipped graphically and left blank, and the following task will begin after the end of the excluded dates. As shown here ![](https://raw.githubusercontent.com/NeilCuzon/mermaid/develop/docs/img/Gantt-long-weekend-look.png) A Gantt chart is useful for tracking the amount of time it would take before a project is finished, but it can also be used to graphically represent "non-working days", with a few tweaks. Mermaid can render Gantt diagrams as SVG, PNG or a MarkDown link that can be pasted into docs. ``` gantt title A Gantt Diagram dateFormat YYYY-MM-DD section Section A task :a1, 2014-01-01, 30d Another task :after a1 , 20d section Another Task in sec :2014-01-12 , 12d another task : 24d ``` ```mermaid gantt title A Gantt Diagram dateFormat YYYY-MM-DD section Section A task :a1, 2014-01-01, 30d Another task :after a1 , 20d section Another Task in sec :2014-01-12 , 12d another task : 24d ``` ## Syntax ``` gantt dateFormat :YYYY-MM-DD title :Adding GANTT diagram functionality to mermaid excludes :excludes the named dates/days from being included in a charted task.. %% (Accepts specific dates in YYYY-MM-DD format, days of the week ("sunday") or "weekends", but not the word "weekdays".) section A section Completed task :done, des1, 2014-01-06,2014-01-08 Active task :active, des2, 2014-01-09, 3d Future task : des3, after des2, 5d Future task2 : des4, after des3, 5d section Critical tasks Completed task in the critical line :crit, done, 2014-01-06,24h Implement parser and jison :crit, done, after des1, 2d Create tests for parser :crit, active, 3d Future task in critical line :crit, 5d Create tests for renderer :2d Add to mermaid :1d section Documentation Describe gantt syntax :active, a1, after des1, 3d Add gantt diagram to demo page :after a1 , 20h Add another diagram to demo page :doc1, after a1 , 48h section Last section Describe gantt syntax :after doc1, 3d Add gantt diagram to demo page :20h Add another diagram to demo page :48h ``` ```mermaid gantt dateFormat YYYY-MM-DD title Adding GANTT diagram functionality to mermaid section A section Completed task :done, des1, 2014-01-06,2014-01-08 Active task :active, des2, 2014-01-09, 3d Future task : des3, after des2, 5d Future task2 : des4, after des3, 5d section Critical tasks Completed task in the critical line :crit, done, 2014-01-06,24h Implement parser and jison :crit, done, after des1, 2d Create tests for parser :crit, active, 3d Future task in critical line :crit, 5d Create tests for renderer :2d Add to mermaid :1d section Documentation Describe gantt syntax :active, a1, after des1, 3d Add gantt diagram to demo page :after a1 , 20h Add another diagram to demo page :doc1, after a1 , 48h section Last section Describe gantt syntax :after doc1, 3d Add gantt diagram to demo page :20h Add another diagram to demo page :48h ``` It is possible to set multiple depenendenies separated by space: ``` gantt apple :a, 2017-07-20, 1w banana :crit, b, 2017-07-23, 1d cherry :active, c, after b a, 1d ``` ``` gantt apple :a, 2017-07-20, 1w banana :crit, b, 2017-07-23, 1d cherry :active, c, after b a, 1d ``` ### Title The `title` is an *optional* string to be displayed at the top of the Gantt chart to describe the chart as a whole. ### Section statements You can divide the chart into various sections, for example to separate different parts of a project like development and documentation. To do so, start a line with the `section` keyword and give it a name. (Note that unlike with the [title for the entire chart](#title), this name is *required*. ## Setting dates `dateFormat` defines the format of the date **input** of your gantt elements. How these dates are represented in the rendered chart **output** are defined by `axisFormat`. ### Input date format The default input date format is `YYYY-MM-DD`. You can define your custom ``dateFormat``. ``` dateFormat YYYY-MM-DD ``` The following formating options are supported: ``` Input Example Description: YYYY 2014 4 digit year YY 14 2 digit year Q 1..4 Quarter of year. Sets month to first month in quarter. M MM 1..12 Month number MMM MMMM January..Dec Month name in locale set by moment.locale() D DD 1..31 Day of month Do 1st..31st Day of month with ordinal DDD DDDD 1..365 Day of year X 1410715640.579 Unix timestamp x 1410715640579 Unix ms timestamp H HH 0..23 24 hour time h hh 1..12 12 hour time used with a A. a A am pm Post or ante meridiem m mm 0..59 Minutes s ss 0..59 Seconds S 0..9 Tenths of a second SS 0..99 Hundreds of a second SSS 0..999 Thousandths of a second Z ZZ +12:00 Offset from UTC as +-HH:mm, +-HHmm, or Z ``` More info in: http://momentjs.com/docs/#/parsing/string-format/ ### Output date format on the axis The default output date format is YYYY-MM-DD. You can define your custom ``axisFormat``, like `2020-Q1` for the first quarter of the year 2020. ``` axisFormat %Y-%m-%d ``` The following formating strings are supported: ``` %a - abbreviated weekday name. %A - full weekday name. %b - abbreviated month name. %B - full month name. %c - date and time, as "%a %b %e %H:%M:%S %Y". %d - zero-padded day of the month as a decimal number [01,31]. %e - space-padded day of the month as a decimal number [ 1,31]; equivalent to %_d. %H - hour (24-hour clock) as a decimal number [00,23]. %I - hour (12-hour clock) as a decimal number [01,12]. %j - day of the year as a decimal number [001,366]. %m - month as a decimal number [01,12]. %M - minute as a decimal number [00,59]. %L - milliseconds as a decimal number [000, 999]. %p - either AM or PM. %S - second as a decimal number [00,61]. %U - week number of the year (Sunday as the first day of the week) as a decimal number [00,53]. %w - weekday as a decimal number [0(Sunday),6]. %W - week number of the year (Monday as the first day of the week) as a decimal number [00,53]. %x - date, as "%m/%d/%Y". %X - time, as "%H:%M:%S". %y - year without century as a decimal number [00,99]. %Y - year with century as a decimal number. %Z - time zone offset, such as "-0700". %% - a literal "%" character. ``` More info in: https://github.com/mbostock/d3/wiki/Time-Formatting ## Comments Comments can be entered within a gantt chart, which will be ignored by the parser. Comments need to be on their own line, and must be prefaced with `%%` (double percent signs). Any text after the start of the comment to the next newline will be treated as a comment, including any diagram syntax ``` gantt title A Gantt Diagram %% this is a comment dateFormat YYYY-MM-DD section Section A task :a1, 2014-01-01, 30d Another task :after a1 , 20d section Another Task in sec :2014-01-12 , 12d another task : 24d ``` ## Styling Styling of the a gantt diagram is done by defining a number of css classes. During rendering these classes are extracted from the ### Classes used Class | Description --- | --- actor | Style for the actor box at the top of the diagram. text.actor | Styles for text in the actor box at the top of the diagram. actor-line | The vertical line for an actor. messageLine0 | Styles for the solid message line. messageLine1 | Styles for the dotted message line. messageText | Defines styles for the text on the message arrows. labelBox | Defines styles label to left in a loop. labelText | Styles for the text in label for loops. loopText | Styles for the text in the loop box. loopLine | Defines styles for the lines in the loop box. note | Styles for the note box. noteText | Styles for the text on in the note boxes. ### Sample stylesheet ```css .grid .tick { stroke: lightgrey; opacity: 0.3; shape-rendering: crispEdges; } .grid path { stroke-width: 0; } #tag { color: white; background: #FA283D; width: 150px; position: absolute; display: none; padding:3px 6px; margin-left: -80px; font-size: 11px; } #tag:before { border: solid transparent; content: ' '; height: 0; left: 50%; margin-left: -5px; position: absolute; width: 0; border-width: 10px; border-bottom-color: #FA283D; top: -20px; } .taskText { fill:white; text-anchor:middle; } .taskTextOutsideRight { fill:black; text-anchor:start; } .taskTextOutsideLeft { fill:black; text-anchor:end; } ``` ## Today marker You can style or hide the marker for the current date. To style it, add a value for the `todayMarker` key. ``` todayMarker stroke-width:5px,stroke:#0f0,opacity:0.5 ``` To hide the marker, set `todayMarker` to `off`. ``` todayMarker off ``` ## Configuration Is it possible to adjust the margins for rendering the gantt diagram. This is done by defining the `ganttConfig` part of the configuration object. How to use the CLI is described in the [mermaidCLI](mermaidCLI.html) page. mermaid.ganttConfig can be set to a JSON string with config parameters or the corresponding object. ```javascript mermaid.ganttConfig = { titleTopMargin:25, barHeight:20, barGap:4, topPadding:75, sidePadding:75 } ``` ### Possible configration params: Param | Descriotion | Default value --- | --- | --- mirrorActor|Turns on/off the rendering of actors below the diagram as well as above it|false bottomMarginAdj|Adjusts how far down the graph ended. Wide borders styles with css could generate unwantewd clipping which is why this config param exists.|1 ## Interaction It is possible to bind a click event to a task, the click can lead to either a javascript callback or to a link which will be opened in the current browser tab. **Note**: This functionality is disabled when using `securityLevel='strict'` and enabled when using `securityLevel='loose'`. ``` click taskId call callback(arguments) click taskId href URL ``` * taskId is the id of the task * callback is the name of a javascript function defined on the page displaying the graph, the function will be called with the taskId as the parameter if no other arguments are specified.. Beginners tip, a full example using interactive links in an html context: ```