Lark Calendar Schedule Management

I. API Basic Information

https://open.feishu.cn/open-apis/calendar/v4

Authorization: Bearer {tenant_access_token}

application/json

II. Calendar Operations

1. Create Calendar

POST /open-apis/calendar/v4/calendars

{ "summary": "Project Calendar" }

III. Schedule Operations

2. Create Schedule

POST /open-apis/calendar/v4/calendars/:calendar_id/events

{
  "summary": "Requirement Alignment Meeting",
  "description": "Discuss Q2 product planning",
  "start_time": { "timestamp": "1770641576" },
  "end_time": { "timestamp": "1770645176" }
}

event_id

POST /open-apis/calendar/v4/calendars/:calendar_id/events/:event_id/attendees?user_id_type=open_id

{
  "attendees": [
    { "type": "user", "user_id": "ou_xxx" }
  ]
}

• The schedule creation interface does not support directly passing attendees; you must complete it in two steps.
• The timestamp must be a second-level string (not milliseconds, not a number).
• You must include the

  user_id_type=open_id

  parameter, otherwise IDs starting with

  ou_

  cannot be recognized.
• Add

  reminders

  to ensure attendees receive notifications.

3. Update Schedule

PATCH /open-apis/calendar/v4/calendars/:calendar_id/events/:event_id

4. Delete Schedule

DELETE /open-apis/calendar/v4/calendars/:calendar_id/events/:event_id

IV. Intelligent Scheduling

5. Batch Query Free/Busy Status

POST /open-apis/calendar/v4/freebusy/list

{
  "time_min": "2026-02-10T09:00:00+08:00",
  "time_max": "2026-02-10T18:00:00+08:00",
  "user_id": "ou_xxx"
}

V. Calendar Subscription

6. Subscribe to Calendar Changes

POST /open-apis/calendar/v4/calendars/:calendar_id/subscribe

VI. Best Practices

1. Check First, Create Later: Use the freebusy API to query available time slots before creating a schedule
2. Second-level String: The timestamp format is the most common pitfall; it must be a second-level string
3. Reminder Settings: Always add reminders, otherwise attendees may easily miss the meeting
4. Subscription Monitoring: Enable subscription for key calendars to achieve real-time awareness of schedule changes