Use YYYY-MM-DD when preparing a CSV so each transaction date has one clear interpretation. For example, 2026-09-30 identifies September 30 without depending on a day-first or month-first setting.
The parser accepts a valid ISO calendar date directly. It still checks that the date exists, so an impossible day is not made valid by using the right layout.
Convert with evidence
- Confirm the original export’s date convention before converting any ambiguous values.
- Create a working copy with the full four-digit year and consistent month and day fields.
- Compare representative converted dates, the first and last dates, and the transaction count with the original.
Keep the bank’s posted date when that is the source date used for the import. Do not substitute the day you downloaded the file or the day you prepared the working copy.
After reading the rows, inspect Date as read and Date together. If the dates are correct but rows are held as Before start date or Closed period, resolve those accounting-period conditions separately. Changing a genuine source date to escape a hold would misstate the activity.
Was this article helpful?
Tell us whether this answered the question you came with.