Formatting Issues

How to Fix Excel Not Accepting Dates in DD/MM/YY Format on Mac

Kushani Nimanthika Sep 25, 2026 869 views

Question details

The user needs to input dates using the day/month/year format, but the software keeps converting or expecting the American month/day/year standard.

How to Enter Dates in DD/MM/YY Format in Excel

Product: Microsoft Excel
Device & OS: macOS
Scenario: Entering date data into Excel spreadsheets for record-keeping or calculations.
Observed behavior: Excel rejects the DD/MM/YY format and automatically defaults to the American MM/DD/YY format regardless of the user's preferred visual format.

Before you start

Before modifying your system settings, verify whether this date formatting issue is occurring across all your workbooks or just within a specific file downloaded from an external source.

Solution 1Recommended

Change macOS System Regional Settings

Excel for Mac relies directly on your macOS system preferences for its default date and time displays. Switching your system region to one that utilizes the DD/MM/YY format will correct this behavior across all spreadsheets.

By default, if your Mac's region is set to the United States, Excel will strictly enforce the MM/DD/YY standard. Adjusting this at the OS level ensures you won't have to manually reformat dates every time you open a new workbook.

Open System Settings

Click the Apple logo in the top-left corner of your screen and select System Settings (or System Preferences on older macOS versions).

Navigate to Language & Region

Click on General in the left sidebar, then select Language & Region on the right.

Adjust the Region

Under the Region section, click the drop-down menu and choose a region that uses the day/month/year format, such as English (United Kingdom) or English (Australia).

Restart Excel

Completely quit Microsoft Excel and reopen it for the new system default settings to take effect.

System-wide Impact: Changing this setting will also update the default date formats in other macOS applications, such as Apple Calendar and Mail.

Solution 2

Apply Custom Date Formatting to Specific Cells

If you prefer to keep your Mac's system region set to the United States but need specific Excel cells to display dates as DD/MM/YY, you can use Excel's Custom Format tool.

Powerful Spreadsheet Alternative

Easily Manage Custom Date Formats with WPS Office

WPS Spreadsheet offers an intuitive cell formatting interface, making it effortless to customize date formats like DD/MM/YY without altering your entire computer's regional settings.

1. Open Your Spreadsheet: Launch WPS Spreadsheet and open the document containing your dates.
2. Highlight Date Cells: Select the range of cells that you want to display in the DD/MM/YY format.
3. Access Format Cells: Right-click your selection and choose 'Format Cells', or press Ctrl+1 (Cmd+1 on Mac).
4. Set the Date Format: Go to the 'Number' tab, select 'Date', choose a locale like 'English (U.K.)', or input 'dd/mm/yy' under the 'Custom' category, then click OK.

Fully compatible with Microsoft Excel (.xlsx) files.Intuitive right-click cell formatting for quick adjustments.Independent locale settings within the spreadsheet.Free and lightweight software for Mac and Windows.

microsoft office alternative - wps office

Frequently Asked Questions

Why does Excel automatically change my DD/MM/YY dates to American format?

Excel defaults to the regional settings configured in your Mac or PC's operating system. If your computer is set to the United States region, Excel will automatically convert or interpret your typed dates into the American MM/DD/YY standard.

Can I use the DD/MM/YY format without changing my entire Mac's region?

Yes. You can override the default setting for specific cells in Excel by highlighting them, right-clicking to select 'Format Cells', navigating to the 'Number' tab, and setting a Custom format to 'dd/mm/yy'.

Will changing the date format alter the actual date value in my calculations?

No. Changing the date format only affects how the date is visually displayed on the screen. The underlying serial number that Excel uses to calculate date differences remains unchanged and accurate.

Excel & Data Problems