Issue with Date Format Interpretation in Power BI

lucaspisso - First thing to check is your Locale for import.  

Navigate to Options and Settings > Current File > Regional Settings and ensure this is set to your Locale:

Next up, you can overwride this at a column level in Power Query:

• Transform data > Transform Editor (Power Query Editor). 
   
• Select the date column you want to format. 
   
• Right-click on the column and choose Change Type > Using Locale. 
   
• In the window that appears, specify the Data Type as Date or DateTime, and then select the appropriate Locale from the dropdown list. 
   
• This allows you to override the default locale for specific columns. 

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Hi mark_endicott,

Changing this setting only affects future data loads, not already loaded data.

lucaspisso, alogwith changing this setting as mentioned by mark_endicott , You should perform below steps in Power Query

Convert Text to Date in dd/mm/yyyy format

1. Open Power Query Editor

2. Select the column

3. Right-click > Change Type > Using Locale...

4. Set:

   • Data Type: Date

   • Locale: English (United Kingdom) (or appropriate)

This forces correct parsing of the text into date values using your intended format.

Format Display of Dates (for visuals)

While this won’t affect parsing, you can format how dates appear:

• In the Data pane, select your Date column

• Under Column tools > Format, choose dd/mm/yyyy

This is for visual consistency, not parsing logic.

Power BI Service Consideration

When publishing to Power BI Service:

• Report viewers see date formats based on their browser or Power BI profile locale

• To enforce consistency:

  • Set report-level language:
    File > Options > Regional Settings > Report Locale

  • Or direct users to set Power BI Service locale in their settings

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