Research · Evaluation & benchmarks
Current date in system prompts skews LLM evaluation results
Dating the Model: Hidden Dates in System Prompts Affect LLM Evaluation
The authors show that LLM accuracy varies by up to 14% on math reasoning and reshuffles leaderboards when only the date changes, making the effect larger than other known sources of non-determinism.
GSM8K: 7.75% worst-to-best date delta in accuracy (as reported)
Johannes Gutenberg University Mainz, Universidad Iberoamericana, University of Colorado Boulder