Research Workbench

Day/month date ambiguity audit

Flag slash-separated dates that admit both day-first and month-first interpretations.

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One DD/MM/YYYY or MM/DD/YYYY token per line

Use exactly two-digit first and second fields and a four-digit year from 1900 to 2100. No automatic conversion is performed.

The starting values are hypothetical. Results update as you edit. Use aggregate or synthetic inputs only.

Calculation results

Date audit: 03/04/2026: AMBIGUOUS | 13/04/2026: day-first only | 02/30/2026: invalid date | 05/05/2026: same date in both formats
Next step: Confirm one documented source format before conversion.

How to interpret the output

A token is ambiguous when both calendar interpretations are valid and different. A date can be unambiguous within this test yet still inconsistent with the source system. Confirm the documented format at import; never resolve mixed-format columns by guessing each row separately.

Method reference

Source checked 2026-11-06. Read the reproducible calculator validation report.