pbiplintRules / Formatting
Provide format string for "Month" columns
What it checks
DateTime columns with month in the name whose format string is not exactly MMMM yyyy.
Why it matters
A DateTime column named Month usually holds the first day of each month, and with a default date format it reads as March 1, 2026 rather than March 2026. The MMMM yyyy format shows the month and year, and setting it on the column fixes every visual at once.
How to fix it
Set the Format under Column tools in Power BI Desktop, or add formatString: MMMM yyyy under the column in the TMDL file. If you prefer a shorter form such as MMM yyyy, set it and turn this rule off in pbiplint.config.json, because only the exact string passes.
Quirks
- The name test is a substring, so any DateTime column with month in its name is checked.