How is Session min (session duration) measured?

Complete sessions: from Operation: Start to the Operation: End (the End without '(1)', i.e. the 告一段落 wrap-up time). Partial sessions (a Start but no End) now also get a duration: from Operation: Start to the last message logged in that occurrence. (Updated 2026-07-13 — status and complete-duration now share the Operation End marker; partial sessions are no longer blank.)
A 2-hour cap is kept for the headline value; longer spans are flagged as ⚠ <time> (>2h) with the raw duration, so long / multi-day occurrences stay visible. Video & audio minutes are measured separately and were not changed.