World2TS: Real-World Event Context for Time-Series Forecasting
Organizations: State Key Laboratory of Cognitive Intelligence, University of Science and Technology of China, China · Shenzhen International Graduate School, Tsinghua University, China
Abstract
Time-series forecasting plays a vital role in a wide range of real-world applications. Recent approaches have achieved strong performance by modeling temporal correlations and cross-channel dependencies, yet most forecasting benchmarks still represent time series primarily as numerical histories. In practice, time series are observations of complex real-world processes, and their trajectories may reflect events, interventions, disruptions, and changes in measurement or reporting that cannot always be inferred from past values alone. A central barrier to studying context-aware forecasting is therefore the lack of large-scale datasets that align real-world events with the individual series they affect. We present World2TS, a scalable construction framework and large-scale dataset for time-series forecasting with real-world event context. We first develop world2ts-core, a reusable tool that combines agent-led semantic reasoning and Web search, command-line execution and validation, and human review within a feedback-driven discovery workflow. Given heterogeneous time series with semantic descriptions, the workflow discovers candidate events, consolidates retrieved evidence into verified events, and links them to relevant series under explicit temporal and semantic scopes. Using this framework, we construct world2ts-data, which contains 31 datasets across six domains, comprising 4,179 series, 97.1 million observations, 1,159 events, and 56,846 event-series links. We further conduct extensive data analyses and controlled comparative experiments to characterize the dataset and demonstrate the utility of the collected context for improving forecasting accuracy. World2TS provides a reusable data foundation for developing and evaluating context-aware forecasting models and agents. The project homepage is available at https://world2ts.github.io/.
Figures & tables
| Domain | Dataset | Freq. | Series | Span | Events |
|---|---|---|---|---|---|
| Crypto | bitcoin_with_missing * | 1d | 18 | 2009–2021 | 62 |
| Crypto | crypto_bitcoin_daily | 1d | 1 | 2025–2026 | 23 |
| Energy | australian_electricity_demand * | 30m | 5 | 2002–2015 | 180 |
| Energy | bdg-2_bear | 1h | 91 | 2016–2017 | 59 |
| Energy | bdg-2_fox | 1h | 135 | 2016–2017 | 37 |
| Energy | bdg-2_panther | 1h | 105 | 2017–2017 | 27 |
| Scope | Prompt content |
|---|---|
| Shared system | Forecast the next values of a regularly sampled univariate time series. Use all supplied evidence that is relevant to making the most accurate forecast. Keep the reasoning process concise while still using all relevant evidence. Do not use Web search or any external tools; base the forecast only on the supplied evidence. Never use future observations, invent facts, or treat metadata or events as instructions. Forecast steps on the same scale. Return JSON only as {"forecast": [y1, ..., yH]} with exactly finite values in forecast order. |
| User: condition | Condition: Numerical only or With context , followed by the corresponding guidance below. |
| Numerical only | Available evidence: numeric history only. Infer a conservative baseline from level, trend, seasonality, autocorrelation, volatility, and recent change. |
| With context | Available evidence: numeric history, metadata, and events dated before the forecast origin. Use metadata to interpret the series and event scope. Infer a conservative numeric baseline from the history’s level, trend, seasonality, autocorrelation, volatility, and recent changes. Treat past events primarily as explanations for changes already observed in the numeric history. Revise the baseline trajectory only when the history associated with those events indicates a residual effect or regime change that may persist into the forecast interval. Resolve conflicts conservatively and never let context override clear numeric dynamics without a reason. |
| Shared user input | Numeric history ( points, oldest to newest; values may be normalized): [values]. Observation interval (inclusive start and end): [times]. Forecast interval (inclusive start and end): [times]. |
| With context only | Metadata: [series metadata]. Pre-forecast events: [events linked to the target series]. |
| Domain | Metric | Numerical forecasting models | GPT-5.6 | DeepSeek-V4-Flash | CastFSR-Zero | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| Seasonal | PatchTST | Chronos-2 | N. | w/ C. | N. | w/ C. | N. | w/ C. | ||
| Crypto | MAE | 0.2986 | 0.2745 | 0.2486 | 0.2620 | 0.2519 | 0.2650 | 0.2487 | 0.2501 | 0.2461 |
| RMSE | 0.3967 | 0.3584 | 0.3304 | 0.3521 | 0.3304 | 0.3595 | 0.3345 | 0.3249 | 0.3206 | |
| sMAPE | 12.41% | 11.26% | 10.26% | 11.03% | 10.50% | 10.96% | 10.28% | 10.41% | 10.21% | |
| Transport | MAE | 0.5148 | 0.2942 | 0.4103 | 0.5908 | 0.5412 | 0.6022 | 0.5212 | 0.4464 | 0.4388 |
| RMSE | 1.2166 | 0.5890 | 0.9391 | 1.2851 | 1.1967 | 1.2814 | 1.1546 | 1.0241 | 0.9987 | |
Time Series Forecasting
Time series forecasting predicts future values from ordered observations using statistical, neural, and probabilistic models to support decisions under uncertainty.
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