Power Pivot Principles: The A to Z of DAX Functions – ENDOFMONTH

In our long-established Power Pivot Principles articles, we continue our series on the A to Z of Data Analysis eXpression (DAX) functions.  This week, we look at ENDOFMONTH. 

The ENDOFMONTH function

The ENDOFMONTH function is one of the time intelligence functions which returns the last date of the month in the current context for the specified column (field) of dates.  It has the following syntax:

It contains one [1] argument:

• dates: this is required which represents a column that contains dates.  This can be any of the following:
• a reference to a date / time column
• a table expression that returns a single column of date / time values
• a BOOLEAN expression that defines a single-column table of date / time values.

It should be further noted:

• this function is not supported for use in DirectQuery mode when used in calculated columns or row-level security (RLS) rules
• the ENDOFMONTH function is similar to the EOMONTH function when the months argument of the EOMONTH function is set to zero [0]. 

Please consider the following example where we have a Dates table with a date range from 1 May 2020 to 1 September 2020:

We can create a simple measure to get the end of the month date for each date in the Start Date column:

Then we can create a PivotTable to view our results:

All the dates return to the last date of the month for the respective month.  However, there is something odd in the PivotTable which is 1 September 2020 is supposed to return 30 September 2020 but, in this case, it does not. 

Therefore, we should note the following when dealing with the time intelligence function:

• all dates need to be present for the years required.  All the days in this span, from January 1 to December 31, must be included in the Date table.  The date table must include all dates from commencement to the last day of a fiscal year if the report solely refers to fiscal years
• a column with a DateTime or Date data type and unique values is required.  Typically, this column is known as Date.  Although it is common practice, this is not necessary when defining associations with other tables.  However, the ‘mark as Date Table’ feature should relate to the Date column, which must have distinct values
• the Date table must be designated as a date table in the model in case the relationship between the Date table and any other table is not dependent on the Date.

Come back next week for our next post on Power Pivot in the Blog section.  In the meantime, please remember we have training in Power Pivot which you can find out more about here.  If you wish to catch up on past articles in the meantime, you can find all of our Past Power Pivot blogs here.