届
jiè · HSK 5
classifier for events, meetings, elections, sporting fixtures, years
📅 届 = measure word for scheduled events like sessions or graduations
届 (jiè) counts numbered occurrences of recurring events: the Nth conference, graduating class, or Olympics. Etymology: 尸 (body) + 由 (cause) — originally meant 'to arrive at a due time', extended to scheduled installments.
届 — corpse radical 尸 + 由
届 originally combined 尸 (a bent body) with a phonetic element, depicting someone arriving at a destination. Over time it came to mean 'to reach,' 'arrive at,' or 'fall due,' and is now used for sessions or terms (e.g., a graduating class) that arrive on schedule.