An alternative-data feature appears too early

A vendor delivers a daily sentiment score labelled with the trading date. What evidence do you need before backtesting it for that day's opening trade?

Obtain the actual publication, collection and revision timestamps, together with a point-in-time delivery history. A date label does not show that the score existed before the open. Verify source-news cutoffs, time zones, processing latency and later corrections. If availability cannot be established, use a conservative feasible delay and describe the remaining uncertainty instead of assuming the label is an availability timestamp.