Normalize mixed dates without guessing silently

Dates such as 03/04 are ambiguous when exports mix regional conventions. A clean output should preserve the original string and flag uncertain interpretations.

Prepare the workbook

Keep an unchanged source copy and explain column meanings, units and date boundaries. Use a spreadsheet or data role with compatible local tools, or the prepared sandbox. Ask for a rejected-row report instead of silently deleting inconvenient records. OfficeCubs text previews do not recalculate formulas; open the final workbook in a spreadsheet application and check representative formulas and totals.

Inputs for this workflow: date-export.csv plus the source system’s stated date convention.

Work through the task

1. Classify recognized formats.
2. Convert unambiguous values and isolate ambiguous ones.

A brief you can adapt

Write normalized-dates.csv with original_date, normalized_date and status. Use YYYY-MM-DD. Mark ambiguous values for review instead of guessing.

The filenames above are examples. Replace them with your actual inputs and destination before submitting the task.

Review the deliverable

Test an unambiguous ISO date, a day above twelve and a month/day pair that could be interpreted both ways.

Where this approach can fail

A locale assumption must come from the source owner, not the majority pattern alone.

For the related desktop setup, see missing document tools.