Week numbers in Outlook
To enable or display the ISO 8601 week number in Outlook, you typically need to adjust the view settings:
File > Options > Calendar > Display options > Check "Show week numbers"
* Ensure your system or application regional settings are set to follow ISO 8601 standards (weeks start on Monday) if the output varies.
Step-by-Step Instructions
- In Outlook for Windows, click File > Options > Calendar.
- Scroll to "Display options".
- Tick "Show week numbers in the month view and in the Date Navigator".
- For ISO numbering, set "First day of week" to Monday and "First week of year" to "First four-day week".
Good to Know
The last step matters: with the default "Starts on Jan 1" rule, Outlook's week numbers disagree with the ISO standard in years where January 1 falls late in the week. "First four-day week" + Monday reproduces ISO 8601 exactly.