ChangeTaskDueDate API

Changes the due date and the allowed start time span of an active workflow task. The new due date must be in the future. The task's reminder date, supervisor notification date, and allowed start date are all recalculated automatically based on the new due date.

The task must be in InProgress or DueDateChanged status — the due date cannot be changed on tasks that have not yet started, or that are already completed, dropped, or reassigned.

Endpoint

/srv.asmx/ChangeTaskDueDate

Methods

• GET /srv.asmx/ChangeTaskDueDate?authenticationTicket=...&taskId=...&newDueDate=...&allowedStartTimeSpan=...
• POST /srv.asmx/ChangeTaskDueDate (form data)
• SOAP Action: http://tempuri.org/ChangeTaskDueDate

Parameters

Response

Success Response

<root success="true" />

Error Response

<root success="false" error="[901] Session expired or Invalid ticket" />

Required Permissions

The calling user must satisfy one of the following conditions:

• The calling user is the task assignee and the task definition has the "Postpone" (change due date) permission enabled for assignees.
• The calling user is a workflow supervisor for this task.

Example

GET Request

GET /srv.asmx/ChangeTaskDueDate
    ?authenticationTicket=3f7a1b2c-4d5e-6f7a-8b9c-0d1e2f3a4b5c
    &taskId=8821
    &newDueDate=2026-03-15T17:00:00
    &allowedStartTimeSpan=24
HTTP/1.1
Host: yourserver

POST Request

POST /srv.asmx/ChangeTaskDueDate HTTP/1.1
Host: yourserver
Content-Type: application/x-www-form-urlencoded

authenticationTicket=3f7a1b2c-4d5e-6f7a-8b9c-0d1e2f3a4b5c&taskId=8821&newDueDate=2026-03-15T17:00:00&allowedStartTimeSpan=24

Success Response

<root success="true" />

Notes

• The task must be in InProgress (status 10) or DueDateChanged (status 20) state. Calling this API on a task with any other status (e.g. NotStarted, Completed, Dropped, Reassigned) returns an error.
• newDueDate must be a future date/time relative to the server clock. Passing a past date/time returns an error.
• The new due date does not need to be later than the current due date — it can also be moved to an earlier future time.
• On success, the following fields are recalculated automatically:
  • Task status is set to DueDateChanged (20).
  • Reminder date is shifted to newDueDate − reminderTimeSpan hours (if a reminder was configured).
  • Supervisor notification date is recalculated from newDueDate.
  • Allowed start date is set to newDueDate − allowedStartTimeSpan hours (or cleared if allowedStartTimeSpan is 0).
  • Any pending reminder, supervisor, and overdue notification flags are cleared.
• allowedStartTimeSpan is in hours. Setting it to 0 removes the allowed-start restriction — the assignee can start the task at any time.
• Use GetTask to retrieve a task's current taskId, status, and assignee before calling this API.

Related APIs

• GetTask – Retrieve the details of a specific task including its current status and due date.
• getTasks – Get a filtered list of tasks to find task IDs.
• ReassignTask – Reassign a task to a different user, optionally with a new due date.
• UpdateTaskFinishDate – Update the recorded finish date of a completed task.
• SetTaskPriority – Change the priority of a task.
• CompleteTask – Mark a task as completed.

Error Codes