In seven years of building Power BI solutions for UK organisations, I've seen one issue more consistently than almost any other: months appearing in the wrong order. Finance directors open a dashboard expecting January, February, March... and see April, August, December... instead. The report is technically accurate—the numbers are correct—but the presentation undermines trust before anyone even looks at the values.
The problem is simple but insidious: Power BI sorts text fields alphabetically by default. Month names are text. Unless you explicitly tell Power BI otherwise, "April" comes before "January", "August" before "February", and so on. For organisations using fiscal years—where October might be month 1 and September might be month 12—this default behaviour creates chaos.
This guide shows you exactly how to fix month sorting in Power BI, with production-ready patterns for both calendar months and fiscal months (including October–September academic years). These are the same approaches I use in real implementations for UK finance and operations teams.
By the end of this guide, you'll understand why month sorting breaks, know how to create sort columns in DAX and Power Query, be able to implement fiscal month ordering for October–September years, and have a troubleshooting checklist for when things go wrong.
Why Month Sorting Breaks in Power BI
Power BI has no inherent understanding of months. It knows about data types—text, numbers, dates—but it doesn't know that "January" should come before "February". When you put a month name field (like "MonthName" from your Date table) into a visual, Power BI treats it as text and sorts alphabetically.
This creates three specific problems that I see repeatedly:
Problem 1: Alphabetical Month Order
Calendar months appear as April, August, December, February, January, June, July, March, May, November, October, September. This is technically correct alphabetical sorting but completely wrong for reporting.
Problem 2: Fiscal Years Sorted as Calendar
Organisations with October–September fiscal years often see their data grouped January–December (calendar order) instead of October–September (fiscal order). Year-to-date calculations are correct, but the visual grouping is misleading.
Problem 3: Auto Date/Time Conflicts
Power BI's Auto Date/Time feature creates hidden date tables that you can't control. These auto-generated tables have month names but no sortable month number, forcing alphabetical order. Disabling Auto Date/Time and building a proper Date Table is the fix.
The solution is consistent across all three problems: create a numeric column that represents the correct order, then tell Power BI to sort the text field by the numeric column. Power BI calls this "Sort by Column". It's simple once you've seen it, but it's not intuitive if you've never encountered it.
Power BI can sort any column by any other column of the same data type (or compatible types). For text fields like month names, we create a corresponding numeric field and use it as the sort key. The numeric field is hidden from the visual but controls the ordering.
Method 1: Sort by Column with DAX
This is the most common approach—creating a calculated column in your Date table and using it as the sort key. I use this pattern in production models because it's explicit, easy to audit, and performs well.
Step 1: Create Month Number Column
Your Date table should already have a month number column. If it doesn't, add it:
Month = MONTH([Date])
This returns 1 for January, 2 for February, ..., 12 for December. It's the calendar month number and serves as our sort key.
Step 2: Create Month Name Column
Again, your Date table probably has this. If not:
MonthName = FORMAT([Date], "MMMM")
This returns the full month name: January, February, etc. It's what displays in your visuals.
Step 3: Apply Sort by Column
Now connect the two columns:
- In Power BI Desktop, select the
MonthNamecolumn in the Fields pane - Go to the Column Tools tab in the ribbon
- Click Sort by Column
- Select
Month(the numeric month column)
That's it. Power BI now knows that MonthName should be ordered by the Month column. Any visual using MonthName will display in calendar order.
After setting Sort by Column, create a simple table visual with MonthName and any measure. If months appear alphabetically, the sort isn't applied. You should see January, February, March... in order. This is the number one mistake I see when reviewing models—developers create sort columns but forget to apply them.
Method 2: Power Query Sort Column
If you create your Date table in Power Query rather than DAX (my preference for production models), you can set the sort order directly in the query editor. This has some advantages: the sort order is embedded in the table definition, and you avoid creating additional calculated columns in DAX.
Step 1: Add Month Number in Power Query
In Power Query Editor, add a custom column:
// Custom Column formula:
Date.Month([Date])
Step 2: Set Sort Order
Right-click the MonthName column and select Sort By Column, then choose your Month number column. Power Query will remember this relationship when loading into Power BI.
The advantage of this approach is that the sort order is defined once, in the query layer, rather than requiring manual configuration after each refresh. For large models or team environments, this reduces the risk of someone breaking the sort order by accidentally clearing column properties.
Both approaches work. DAX gives you more flexibility (you can create multiple sort columns for different purposes), while Power Query embeds the sort order in the table definition. I typically use DAX for fiscal calendars (where I need multiple sorting schemes) and Power Query for simple calendar month sorting.
Fiscal Month Sorting (October–September)
For UK organisations using October–September fiscal years—common in education, charities, and some public sector bodies—the approach is similar but requires a different numeric sequence. October needs to be month 1, November month 2, ..., September month 12.
Step 1: Create Fiscal Month Number
Add this calculated column to your Date table:
Fiscal Month Num =
IF(
MONTH([Date]) >= 10,
MONTH([Date]) - 9,
MONTH([Date]) + 3
)
Here's the logic: if the calendar month is October (10) or later, subtract 9 to map October→1, November→2, December→3. If the calendar month is before October, add 3 to map January→4, February→5, ..., September→12.
Step 2: Create Fiscal Month Name
You want the display to show the actual month name, not "Fiscal Month 1", "Fiscal Month 2", etc. Use this formula:
Fiscal Month Name =
FORMAT(
DATE(YEAR([Date]), [Fiscal Month Num] + 9, 1),
"MMMM"
)
This is a clever trick: we create a date where the month is our fiscal month number plus 9 (to shift back to calendar months), then FORMAT converts it to the month name. Fiscal month 1 becomes October (month 10), fiscal month 2 becomes November (month 11), and so on.
Step 3: Apply Sort by Column
The process is identical to calendar months: select Fiscal Month Name → Column Tools → Sort by Column → select Fiscal Month Num.
Now your fiscal months will sort correctly: October, November, December, January, February, ..., September. This is essential for fiscal year reporting where the visual grouping must match the organisation's financial year.
I've seen models where fiscal month names are created but the sort isn't applied—or worse, the sort is applied to the calendar month number. The result shows October, November correctly, but then January appears before December. Always verify your sort columns with a table visual before relying on them in production reports.
Visual Examples: Table, Bar Chart, Line Chart
Month sorting matters across all visual types. Here's what correct sorting looks like in three common visuals—and how to verify each is working correctly.
Example 1: Table Visual
Tables are where month sorting problems are most obvious. A well-structured table shows months in chronological order with measures side by side for easy comparison.
How to verify: Create a table with MonthName on rows and any measure as values. Months should appear January→December (or October→September for fiscal). If you see April first, the sort column isn't applied.
Example 2: Bar Chart
Bar charts with months on the x-axis rely on correct sorting for time-based comparisons. A sorted bar chart lets users compare performance across months and spot trends that would be invisible with alphabetical ordering.
How to verify: Create a bar chart with MonthName on the x-axis. The bars should appear left-to-right in month order. Users should be able to scan from left to right and see the progression of time. Alphabetical order would scatter months randomly, making trend analysis impossible.
Example 3: Line Chart
Line charts for time series data are particularly sensitive to month sorting. The line should connect January to February to March..., not jump randomly between months. Correct sorting ensures the line tells a coherent temporal story.
How to verify: Create a line chart with MonthName on the x-axis. The line should progress smoothly from the first month to the last month in your sequence. If the line zig-zags or appears "broken", your months aren't sorted correctly.
For organisations using fiscal years, I recommend using fiscal month names consistently across all visuals. This means your x-axis always shows October→September, even for visuals that might not intuitively need it (like a breakdown by department). Consistency helps users avoid cognitive load—they don't need to remember whether this visual uses calendar or fiscal months.
Troubleshooting Checklist
After reviewing hundreds of Power BI models, I've found that month sorting issues usually stem from one of a handful of root causes. Use this checklist to diagnose and fix problems systematically.
Sort column created? Verify that you have a numeric month column. Without a numeric column, you can't sort a text field correctly.
Sort by Column applied? This is the most common mistake. Creating the column isn't enough—you must explicitly apply Sort by Column from the Column Tools tab.
Correct column selected? I've seen developers sort Fiscal Month Name by Month (calendar month number) instead of Fiscal Month Num. This gives wrong results for fiscal years.
Data type correct? The sort column must be numeric (whole number). If your month column is formatted as text (even if it looks like numbers), Sort by Column won't work.
Auto Date/Time disabled? If Auto Date/Time is enabled, Power BI creates its own month hierarchy that may override your custom Date table. Disable it in Options > Current File > Data Load > Time Intelligence.
Relationships correct? If your fact table relates to a different Date table (or no Date table), your month names won't use the sort columns you defined. Verify all fact tables relate to your Date table.
Visual using correct field? Sometimes visuals use the wrong field—perhaps a text field from the source instead of the MonthName from your Date table. Check the field being used in the visual.
Refresh after changes? Sort by Column changes may not appear until you refresh the visual. Use the refresh button on the visual or press Ctrl+Shift+R to refresh the page.
Model refreshed? If you've made changes to the data model (added columns, changed relationships), refresh the model before testing visuals.
Multiple month columns? Some models have Month, MonthName, FiscalMonth, FiscalMonthName. Ensure you're sorting the correct text column by the correct numeric column for your use case.
Whenever I review a model, I create a simple table visual with the month name on rows and a measure on values. If months aren't in the expected order, I know immediately that sort columns aren't applied correctly. This 30-second test catches 90% of month sorting issues before they reach end users.
Not Sure If Your Model Is Set Up Correctly?
After seven years reviewing Power BI models, I've learned that small issues with sorting and data modeling compound into bigger problems. A Power BI audit can identify month sorting issues, fiscal year problems, and data modeling concerns before they undermine user trust.
Book a Power BI AuditRelated Services
Month sorting is one aspect of building robust Power BI reports. For comprehensive fiscal year implementation, see my guide on setting up a custom fiscal year Date Table in Power BI, which covers fiscal year columns, quarters, and time intelligence patterns.
If your Power BI reports are still loading slowly even with correct sorting, read our comprehensive guide on Power BI performance optimisation for practical fixes.
Digital Adaption provides comprehensive Power BI consultancy services including dashboard development, data modeling reviews, and team training.
Need help with your Power BI implementation? Book a free 30-minute consultation to discuss your challenges and whether I can help.
Frequently Asked Questions
To sort months chronologically in Power BI, create a numeric month column (using MONTH([Date]) for calendar months or a custom DAX formula for fiscal months), select your month name column in the Fields pane, go to Column Tools > Sort by Column, and choose the numeric month column. This ensures months appear in January-February-March order instead of alphabetical April-August order.
Select the month name column (like MonthName) in the Fields pane, navigate to the Column Tools tab in the ribbon, click "Sort by Column", and select the corresponding numeric month column. Power BI will now sort the month names by the numeric values instead of alphabetically. You can verify this worked by creating a table visual—months should appear in chronological order.
Power BI months sort alphabetically because Power BI treats text fields as text by default, sorting A-Z. Month names are text fields, so without explicit sorting instructions, April comes before January. The fix is to create a numeric month column and use "Sort by Column" to tell Power BI to sort the month name text field by the numeric month field instead.
Create a fiscal month number column using IF(MONTH([Date]) >= 10, MONTH([Date]) - 9, MONTH([Date]) + 3), which maps October to 1, November to 2, through September to 12. Create a fiscal month name column using FORMAT with the fiscal month number. Then apply Sort by Column to sort Fiscal Month Name by Fiscal Month Num. This ensures your fiscal months appear October→September.
Check: (1) Sort by Column has been applied, not just the column created, (2) you're sorting by the correct numeric column (Month not another field), (3) the sort column is numeric not text, (4) Auto Date/Time is disabled, (5) your visual is using the month name from your Date table not a text field from source data, and (6) you've refreshed the visual after applying Sort by Column.
Ensure your Date table has fiscal month columns (Fiscal Month Name and Fiscal Month Num). Put Fiscal Month Name on the x-axis of your bar chart. Apply Sort by Column to sort Fiscal Month Name by Fiscal Month Num. The bars will now appear in fiscal month order (October through September) instead of alphabetical or calendar month order.
Yes, in Power Query Editor, right-click your month name column and select "Sort By Column" then choose your numeric month column. Power Query embeds the sort order in the table definition, which persists across refreshes. This approach avoids creating additional DAX calculated columns and is my preference for production models where the sort order is stable.
For calendar months, ensure MonthName is sorted by Month using Sort by Column. For fiscal months, ensure Fiscal Month Name is sorted by Fiscal Month Num. If months still appear incorrectly, check that your table visual is using the month name field from your Date table, not a text field from your source data. You can verify the correct field is being used by checking the Fields pane while the table visual is selected.
The DAX formula for fiscal month number (October to September) is: Fiscal Month Num = IF(MONTH([Date]) >= 10, MONTH([Date]) - 9, MONTH([Date]) + 3). This assigns October=1, November=2, December=3, January=4, February=5, March=6, April=7, May=8, June=9, July=10, August=11, September=12. Use this with Sort by Column to correctly order fiscal months.
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