Converting Numeric Fields (1.5) into Time Fields (1:30) in Tableau

By: Eric Parker

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Eric lives in Seattle and has been teaching Tableau and Alteryx for 5 years. He's helped thousands of students solve their most pressing problems. If you have a question, feel free to reach out to him directly via email.

Imagine you are working with a data set in Tableau that displays minutes and seconds in decimals. For instance, 1.5 would be reflective of 1 minute and 30 seconds.

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You want that 1.5 to show up at 1:30 instead. Here’s how you can write some calculated fields to accomplish that. Unfortunately, Tableau doesn’t a field type called “time” and there is no default conversion process. However, with some creativity, we can still get the desired result.

First, we will create a calculated field to calculate the seconds value.

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Here is an explanation for why each of the components of the above calculation are necessary;

STR: The average processing time calculation is numeric. In order to do string manipulation (to split off the last two characters), it must be a string field.

SPLIT: Because we are just calculating seconds, we want to ensure we are splitting the original values so we only get the characters after the period.

LEFT: Tableau doesn’t know at what point it should naturally stop grabbing more characters at the end of a split so if the full value was 2.1243 the split would return 1243 instead of just 12. LEFT allows us to grab only the first two characters.

INT: In order to use the value we just grabbed to calculate seconds it must be a numeric field.

ZN: If the value is 0 return a zero for the calculation.

*.01: Each Value should represent a fraction of a minute so we must multiple the returned value by .01.

*60: By multiplying .5 by 60 we can return 30 seconds.

 

Now, in order to get the single digit seconds (like 0) to show up as two digits (00), we need a calculation like this;

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In essence, this calculation determines if the string is a single digit. If so, it adds a leading 0. If not, it doesn’t. 

The Minutes calculation is much simpler.

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To calculate the minute value you can split off whatever comes before the period in the Average Processing Time field.

The last calculation combines the minutes and seconds calculations into a single value.

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This same approach can be used to calculate hours and minutes in the place of minutes and seconds.