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Auto-scheduling is a PRO feature. See licensing and trial info.
Auto-scheduling lets the Gantt automatically move tasks forward whenever an upstream task changes. When enabled, any task linked by a Finish-to-Start dependency is rescheduled so it starts no earlier than its predecessor ends. This removes the need to manually adjust dates throughout a dependency chain.

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The schedule Prop

Pass a schedule object to the <Gantt> component to configure scheduling behaviour. 
interface IScheduleConfig {
  type?: "forward";  // scheduling direction — only forward mode is supported
  auto?: boolean;    // when true, reschedules on every data change automatically
}
PropertyTypeDefaultDescription
type"forward"—Scheduling algorithm. Only forward scheduling is available.
autobooleanfalseWhen true, tasks are rescheduled automatically on every change.

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The summary Prop

The summary prop controls automated behaviour for summary (parent) tasks. 
interface ISummaryConfig {
  autoProgress?: boolean;  // auto-calculate summary task progress from children
  autoConvert?: boolean;   // auto-convert a task to a summary when children are added
}
PropertyTypeDescription
autoProgressbooleanRecalculates the progress of summary tasks based on child task progress.
autoConvertbooleanAutomatically changes a task’s type to "summary" when child tasks are added.

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Forward Scheduling Mode

In forward scheduling mode (type: "forward"), the engine starts from the project start date and propagates task dates forward along the dependency chain:
  1. Tasks with no predecessors are placed at the projectStart date.
  2. Each Finish-to-Start (e2s) link causes the target task to start on or after the source task’s end date.
  3. If auto: true, this recalculation runs on every task edit, drag, or resize.
Links with a lag value are respected — the target task starts lag working days after the source ends (when a calendar is configured).

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Basic Example

The demo below enables auto-scheduling with a fixed project start date. Moving or resizing any task propagates the change through the dependency chain automatically. 
<script>
  import { getData } from "../data";
  import { Gantt, Editor, ContextMenu } from "@svar-ui/svelte-gantt";

  let api = $state();
  let projectStart = $state(new Date(2026, 3, 2));
  const data = getData();
</script>

<Editor {api} />
<ContextMenu {api}>
  <Gantt
    bind:this={api}
    tasks={data.tasks}
    links={data.links}
    scales={data.scales}
    schedule={{ auto: true }}
    {projectStart}
    projectEnd={new Date(2026, 5, 2)}
  />
</ContextMenu>

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How Finish-to-Start Scheduling Works

When schedule.auto is true, every e2s (end-to-start) link is evaluated after each change:
  • The source task finishes at a calculated date.
  • The target task start is pushed to match or exceed the source end date.
  • The target’s end date shifts by the same offset, preserving duration.
  • The cascade continues down the dependency chain recursively.
Combine schedule with the Calendar prop so that scheduling respects working days and hours. Durations are measured in working time when a calendar is active.

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Controlling Project Bounds

Use projectStart and projectEnd props to constrain the scheduling window: 
<Gantt
  tasks={data.tasks}
  links={data.links}
  scales={data.scales}
  schedule={{ auto: true }}
  projectStart={new Date(2026, 3, 2)}
  projectEnd={new Date(2026, 5, 2)}
/>
Tasks will not be scheduled before projectStart. The projectEnd date is used by the Critical Path engine to identify late tasks.

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