Tableau usage enhancements with Date functions

By Sreekesh Eyyapadi, Technical Lead, CRG Solutions 

There are many date functions in Tableau. Some manipulate dates, some convert data to dates, some identify if data is a date. This article will run through the main date functions and give some usage examples  

• Finding the latest DATE in the data source 

{MAX([OrderDate])} 

This formula will return the maximum date and is also usable in other calculations. It’ll appear in the list of available Dimensions for use elsewhere. 

• The Tableau ISDATE function – is my DATE field recognised as a DATE? 

ISDATE([Field]) 

To test which values are recognised by Tableau as being a valid date, use the ISDATE() function. The function is boolean, it returns True for records identified as dates and False for those Tableau doesn’t think are dates. 

• Identify the latest month 

DATETRUNC(‘month’,{MAX([OrderDate])}) 

This formula finds the latest date in the dataset, then sets that date to the first of the month. 

• Identify the same MONTH last year 

DATEADD(‘year’,-1,DATETRUNC(‘month’,{MAX([OrderDate])})) 

Similar to above, but this time also incorporate a DATEADD to find the same month last year.