One instant, two labels
The illustrative timestamp 2026-10-20 00:00 UTC is 09:00 in Korea. Relabelling the clock can identify the same observation. Deciding which time zone defines midnight-to-midnight bars is a different question.
A hypothetical boundary experiment
Let prices at UTC 00:00 and 15:00 be 100 and 104, and the following day's corresponding prices be 102 and 101. UTC-midnight endpoints give a 2% rise. UTC-15:00 endpoints, corresponding to Korean midnight, give about a 2.885% fall. The observation windows differ.
Display settings are not aggregation instructions
TradingView distinguishes exchange time from chart display time. Changing the displayed time zone does not establish that every provider's daily bars were recalculated at the chosen local midnight. Pine's calculation time zone is also distinct from chart display settings.
Binance documents separate meanings for its candle time-zone option and the UTC interpretation of startTime and endTime. A screenshot labelled “Korean time” is therefore incomplete documentation of the aggregation method.
Record four fields
Save provider and symbol, bar interval and endpoints, display time zone, and aggregation boundary rule. Mark unavailable observations as missing. If you carry the last price across a closed session, record that processing choice rather than implying continuous trades.