Provide exactly one of studentId or studentExternalReferenceId. Optional courseId/courseExternalReferenceId filters are mutually exclusive. References match API_ID within the authenticated school; unknown references return an empty list. One row per missed course, including student names, external references, course context and linked justification metadata (no private comments or documents). Unset metadata is omitted. Justification dates describe its own period, which can span multiple courses; reasonName is the current school label when available. Dates are school-local calendar filters; sessions must have ended. Pending includes a justification request or an open email signature window. Hours are the planned course duration. The date range has no maximum span so integrations can retrieve a complete academic year or multi-year history for one student. Prefer shorter periods for large histories: pagination bounds the response, but the total count still evaluates the requested period.