DAX Formula for Calculating Daily Volume One Month Prior

Formula

To calculate the daily volume for a specific time period exactly one month prior, you can use the following DAX formula. This assumes you have a column named Volume and a date column named Date in your table.

DailyVolumeOneMonthPrior = 
VAR CurrentDate = MAX(Table[Date])
VAR OneMonthPriorStart = EDATE(CurrentDate, -1)
VAR OneMonthPriorEnd = EDATE(CurrentDate, -1)
RETURN 
    CALCULATE(
        SUM(Table[Volume]),
        FILTER(
            Table,
            Table[Date] = OneMonthPriorStart
        )
    )

Explanation

1. Variable Declaration:

   • CurrentDate: This variable captures the maximum date in the current filter context.
   • OneMonthPriorStart: Calculates the date one month prior to the CurrentDate using the EDATE function.
   • OneMonthPriorEnd: In this context, it’s not necessary to define an end since we are focusing only on one day, but it can be useful for broader applications.

2. CALCULATE Function:

   • The CALCULATE function modifies the filter context to compute the sum of the Volume column.

3. FILTER Function:

   • The FILTER function is applied to the table to restrict the context such that only the data for the calculated OneMonthPriorStart date is considered.

4. Return Value:

   • The formula returns the total volume for the calculated date, effectively giving you the daily volume from one month prior.

Practical Example

Consider you have the following data set in your table:

• If the current context is set to 2023-10-01, the DailyVolumeOneMonthPrior formula computes the daily volume for 2023-09-01, which would yield a result of 100.

Application Scope

This formula is useful in scenarios where:

• You need to perform month-over-month comparisons.
• You are analyzing historical sales volumes, user activity, or any time-sensitive metrics that require precise day-to-day analysis.

Learning Resources

For further comprehension and advanced usage of DAX, consider exploring the resources available on the Enterprise DNA Platform, where you can find courses specifically designed for enhancing your DAX skills and data analysis capabilities.