> 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. Gantt charts illustrate the start and finish dates of the terminal elements and summary elements of a project.
## excludes (excludes specified day, i.e, "weekends", saturday, sunday, monday, or specific dates, making it useful for computing the amount of time it will take before a project is finished, not the amount of time and effort spent on a project, by individual contributors.
important note when using exclude function, the graphic will accomodate the exclusion of certain days. however, if the date being excluded is inside the time alloted for a task, by adding an extra day to the duration of the task, rather than creating a gap within the scheduled task.
## present some screenshots to show for it and the math to back it up.
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
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;
}
```
## 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
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: