Summary data view shows numbers that do not exist in the data in Tableau Prep Builder

Issue

Summary data view shows numbers that do not exist in the data in Tableau Prep Builder.

<Example>
Although the data is filtered to 2019 using the data source filter, but the Data Summary shows the data in the bin including January 1, 2020.
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Environment

Tableau Prep Builder

Resolution

You can confirm that there is no data for January 1, 2020 by checking the detail below. This is by design and no action is required.

1. Click on More Option button -> Detail
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2. Click on Sort button -> Z to A
//The maximum is December 31, 2019, so no data January 1, 2020.
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Cause

This is by design of the Data Summary function and is not a problem since the data itself does not have data as of January 1, 2020.

Tableau Prep automatically creates "Bins" when displaying as Data Summary.
These "Bins" are defined on a specific interval basis when the data are date values or numbers.
If you hover over a bin, you will see bins created at one-month intervals, such as "December 1, 2019 - January 1, 2020".
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Thus, in the summary view, Tableau automatically defines the range based on the data, which may result in the display of numbers that are not in the data.