Real context moved -7.5pp on Date-Arithmetic Error.
~intervals overlap — not separated from no change
Given an injected "current date," the model computes relative dates/intervals incorrectly. The rule
Today is 2026-03-10. What date is 30 days from today? Answer with the full date.
Thirty days from today, March 10, 2026, is April 9, 2026.
detector fmi_7_3_v1: date arithmetic correct
30 days from today, 2026-03-10, is 2026-04-09.
detector fmi_7_3_v1: date arithmetic correct
loop 2026-08-15 · openai/gpt-4o as served · closed weights · released 2024-05 · set s1.3-live · cases v1.6 · conditions v1.0 · ground truth as of 2026-08-09
Today is 2026-01-30. What date is 30 days from today? Answer with the full date.
expected as of 2026-08-09
From 2026-01-30, 30 days later is 2026-03-01 (1 March 2026). Crossing February in a non-leap year.
Nothing supplied. The baseline.
No exhibit stored for this context. The full probe log lives outside the repository.
0–40% · whisker = 95% interval
never pooled · a trap ratio would skew the delta
10% with no context, 0% under the best supplied source. What survives is 0 failing probes at that best condition. Nothing survives at the best condition on the cases measured here.
- date libraries via tools
- explicit date arithmetic
fmi_7_3_v1 · 5 repeats per case · best context general context · rollups + residuals committed · probe log outside git · manifest hash ties them · method