How to Fix Excel for the Web Not Supporting the 1904 Date System
Question details
The user needs to open a desktop Excel workbook that uses the 1904 date system in Excel for the Web without date values changing or showing errors.
- Product
- Microsoft Excel for the Web
- Device & OS
- not provided
- Scenario
- A desktop workbook using the 1904 date system was uploaded and opened in Excel for the Web.
- Observed behavior
- Excel for the Web changed the date system and displayed errors for negative date values.
Confirm whether the workbook uses the 1904 date system by checking File > Options > Advanced in the Excel desktop app. Make note of any cells that contain negative date values before converting the workbook.
Convert the Workbook to the 1900 Date System in Excel Desktop
Use this solution when you need to view and edit the workbook in Excel for the Web without date errors.
Excel for the Web does not have the Advanced option that enables the 1904 date system, so converting the workbook to the 1900 system is the most reliable way to make it compatible.
Open the affected workbook in the Excel desktop application, not Excel for the Web.
Go to File > Options > Advanced, scroll to the 'When calculating this workbook' section, and clear the 'Use 1904 date system' check box.
After switching to the 1900 date system, adjust affected date values by 1,462 days where necessary.
Save the converted workbook and upload or reopen it in Excel for the Web to confirm dates display correctly.
Keep Using Excel Desktop for Workbooks That Require the 1904 Date System
Use this solution when the workbook must remain on the 1904 date system or when you cannot convert the date values.
Use WPS Office to Open Excel Workbooks That Need the 1904 Date System
If Excel for the Web keeps changing the 1904 date system, WPS Office is a free, lightweight office suite that opens and edits Excel workbooks on the desktop with familiar formatting and strong compatibility.
Frequently Asked Questions
Why doesn't Excel for the Web support the 1904 date system?
Excel for the Web lacks the desktop Advanced option that enables the 1904 date system, so it automatically uses the 1900 date system when opening workbooks.
How do I know if my workbook uses the 1904 date system?
Open the workbook in Excel desktop, go to File > Options > Advanced, and check whether 'Use 1904 date system' is selected under 'When calculating this workbook'.
How many days do I need to adjust when converting from the 1904 to the 1900 date system?
The date serial difference is 1,462 days. Add or subtract 1,462 days to affected date values after switching to the 1900 system.
Can I keep using the 1904 date system if I only work in Excel desktop?
Yes. Excel desktop supports the 1904 date system, so you can keep the workbook unchanged and avoid opening it in Excel for the Web.
Is WPS Office a compatible alternative for opening Excel workbooks with the 1904 date system?
WPS Office is a free desktop spreadsheet alternative that opens and edits .xlsx files with strong Microsoft Excel compatibility, making it a practical option when Excel for the Web is limited.
