getSubtaskDates

calculates the combined start/end dates of tasks nested in a project or another task

task_id

string|number

the task's id, root_id will be used if not specified

object

an object containing the start_date and end_date properties

Example

// duration of the whole project
let dates = gantt.getSubtaskDates();
const dateToStr = gantt.templates.task_date;
 
console.log(`${dateToStr(dates.start_date)} - ${dateToStr(dates.end_date)}`);
 
// duration of the subproject
dates = gantt.getSubtaskDates(1);
 
console.log(`${dateToStr(dates.start_date)} - ${dateToStr(dates.end_date)}`);

The method returns an object containing the start date of the earliest subtask and the end date of the latest subtask.

The return object has the following format:

{
  start_date: Date|null,
  end_date: Date|null
}

If a Gantt chart has any scheduled tasks, both properties will have date values. If the Gantt chart is empty or contains only unscheduled tasks, both properties will have null values.

Back to top