You might want to create a custom date if you always use a date at a specific level, or if you want to create calculations that rely on a binned or truncated date.
You can create a custom date by working in the Data pane or by using
DATETRUNC functions in
a calculated field.
The custom date you create becomes a new field in the Data pane.
Right-click (Control-click on Mac) a date field in the Data pane and select Create > Create Custom Date.
In the Create Custom Date dialog box, type a name for the custom date, such as Date (Quarter, Year).
From the Detail list, select the level you want to show the date at.
Specify whether you want the custom date to be discrete (select Date Parts) or continuous (select Date Value).
When you are finished, click OK.
Example - format column headers as Month, Day, Year
To format column headers as Month, Day, Year (for example, January 1, 2011), follow the steps below. This example uses the Sample - Superstore data source provided with Tableau Desktop.
Drag [Order Date] to Columns.
Drag Sales to Rows.
Right-click (Control-click on a mac) [Order Date] on the Columns shelf and choose More > Custom.
In the Custom Date dialog box, choose Month / Day /Year from the Detail drop-down list.
The view now has the column headers in the correct format: