Power BI DAX: CALENDAR, DATE, YEAR, TODAY

DateTable =
CALENDAR ( DATE ( 2020, 1, 1 ), DATE ( 2022, 12, 31 ) )

To create a Date Table in Power BI using a DAX expression, you can use the CALENDAR or CALENDARAUTO functions.

The CALENDAR function allows you to specify a date range, while CALENDARAUTO automatically generates a date range based on the data in your model. For example, you can create a Date Table by navigating to the "Modeling" tab, selecting "New Table," and entering a DAX formula like the following:

This will generate a table with a single column of dates, which you can then extend with additional calculated columns to support your date interval filtering and grouping needs.

Scenario

Retail Sales Analysis Over a Decade Objective: The company wants to analyze sales data from the past 10 years to identify trends, seasonal patterns, and growth opportunities.

Sample Data

DAX Code to Create Date Table

DateTable =
VAR var1 =
    YEAR ( TODAY () )
RETURN
    CALENDAR ( DATE ( var1 - 9, 01, 01 ), DATE ( var1, 12, 31 ) )

Explanation

• DateTable: This variable creates a table with dates spanning from January 1, nine years before the current year, to December 31 of the current year.

• var1: Captures the current year using the YEAR(TODAY()) function.

• CALENDAR: Generates a continuous range of dates from the start date (DATE(var1 - 9, 01, 01)) to the end date (DATE(var1, 12, 31)).

Analysis

Using this Date Table, the company can now perform various analyses, such as:

• Year-over-Year Growth: Calculate the percentage growth in sales each year.

• Seasonal Trends: Identify peak sales periods and seasonal patterns.

• Long-term Trends: Analyze overall sales growth or decline over the decade.

• Comparative Analysis: Compare sales performance across different years to identify best and worst-performing years.

This approach helps the company gain valuable insights into its sales performance, enabling data-driven decision-making and strategic planning.