When LLMs Meet Time: Why Time-Series Reasoning Is Still Hard
Dashboard numbers are seductive because they look obedient. Revenue goes up, traffic dips, latency spikes, inventory turns over, temperature drifts, volatility clusters. Put the sequence into a chart and the pattern seems almost polite. Then someone asks an LLM what happened. The model answers fluently. It may even sound like an analyst who has seen too many quarterly review decks and has developed a protective layer of confidence. But fluency is not temporal understanding. A model can describe a curve, name a trend, and still fail to understand which segment comes next, whether a transformation is correct, or whether a discontinuity is an error or a legitimate feature of the process. ...