Daily DAX : Day 313 DAY

Power BI DAX DAY Function

Description

The DAY function in DAX (Data Analysis Expressions) returns the day of the month (an integer from 1 to 31) from a specified date.

Syntax

DAY(<date>)

Parameter:

• <date>: A date in datetime format, or a reference to a column containing dates.

Return Value: An integer between 1 and 31 representing the day of the month.

Use Case

The DAY function is used to extract the day component from a date for analysis, filtering, or calculations in Power BI reports. Common scenarios include:

• Analyzing trends based on specific days of the month (e.g., sales on the 1st vs. the 15th).
• Creating custom date-based calculations, such as grouping data by day.
• Filtering reports to focus on specific days (e.g., transactions occurring on the last day of the month).

Example

Suppose you have a table named Sales with a column OrderDate. To extract the day of the month for each order:

DayOfOrder = DAY(Sales[OrderDate])

If OrderDate is 2023-10-15, the function returns 15.

Notes

• The input date must be in a valid datetime format.
• If the input is blank or invalid, the function may return an error or unexpected results.
• Often used with other DAX date functions like MONTH or YEAR for comprehensive date analysis.