For AI agents: markdown of this page — /docs-content-en/entities/activities/deadline.md documentation index — /llms.txt

Set an activity deadline

POST /v1/activities/:id/deadline calls crm.timeline.activity.setDeadline.

JSON

{"deadline":"2026-10-01T12:00:00Z"}

Success: HTTP 200 with the read-back activity in data. The service checks the deadline after the call: if Bitrix24 reports success without changing it, the response is 422 ACTIVITY_DEADLINE_UNCHANGED.