How to use this tool
Enter the exact date-column header. Review ambiguity leaves values such as 03/04/2026 unresolved while accepting unambiguous numeric dates. Choose a verified day-first or month-first rule to apply that convention consistently to non-ISO dates.
Only numeric dates with a four-digit year and YYYY-MM-DD inputs are supported, from 1900 through 9999. Timestamps and timezone conversions are outside the tool's scope. The download is a review report; it does not overwrite the original data.
Check the built-in sample
The sample in Review ambiguity mode produces four converted dates, one ambiguous value, one invalid value, and one blank. With a fixed convention, conflicting values become invalid.
Limits and the downloaded report
The parser supports comma, semicolon, and tab delimiters, quoted separators, escaped quotes, and multiline fields. It reads UTF-8 text, with an optional byte-order mark. An unclosed quote or an invalid field boundary stops processing. Large files should be handled in an appropriate local spreadsheet or data application.
Data remains in memory until you clear or leave the page. The tool does not save it to browser storage. Reports retain unresolved findings. Formula-like text is prefixed with an apostrophe in downloaded review reports; this is a deliberate report-only change. CSV does not define text column types, so import identifiers as Text.