Date formatting and text strings
08 July 2026The Code of Practice requires publishers to offer tabular versions of their COUNTER reports. Most providers offer two formats: tab separated files (.tsv) and Excel files (.xlsx).
We also specify that date fields in COUNTER reports need to be a text string in the YYYY-MM-DD format. Dates show up in the report header and in the table headings for month-by-month usage. Why don’t we specify storing dates in the custom date format in the Excel version of reports? Simple: because spreadsheet programs handle dates differently!
What happens to dates in spreadsheets?
If you open a tabular file in Excel or Google Sheets, it might “guess” that the date fields should be in a date format. What the program displays will depend on two things:
- Where your computer thinks you are
- Which specific date format you have configured in the spreadsheet application.
For example, 2025-12-28 could be Dec-2025 if you’ve set up for the USA, but Dez-2025 in Germany. The same happens with date formats in .xlsx files. Using a text string means you can be sure which dates are in the report. Of course, if you want to put in formatting, you can.
The validator does check dates in COUNTER reports, but it is set up to deliver a Warning when it detects a date format in a .xlsx report. So if you see “Could not check the date format used for the column heading for monthly counts, using date formats is not recommended because the result might depend on the operating system and spreadsheet application settings”, now you know why!