Values Become NULL When Converted From String to Date by A Calculation Field on Prep Flow and Run by CLI

Published: 31 May 2019
Last Modified Date: 06 Jun 2019


In a Tableau Prep flow, values become NULL when converted from String (yyyymmdd) to Date by a calculation field using DATE() or DATETIME() when run by CLI.


  • Tableau Prep
  • Other than English (en_US) locales OS


Try one of the following workarounds. 

Option 1

Change the data type of the field from String to Date/Date Time, not creating DATE() or DATETIME().

Option 2

Use DATEPARSE() to replace DATE()

Option 3

Add "appSettings" session with locale value to this fixed config file.  The file is located under C:\Program Files\Tableau\Tableau Prep Builder <Version>\resources\app\default-settings.json.

It is necessary to add "appSettings" session at the end of the file, which should be a separate session from "featureFlags" session.
Shown below as an example:
"appSettings": {
  "textLocale": "zh_CN",
  "recommendationsDisabled": false,
  "barChartMotionAnimationEnabled": true

Locale value should be:
zh_CN - 简体中文
fr_FR - Français
de_DE - Deutsch
ja_JP - 日本語
ko_KR - 한국어
pt_BR - Português
es_ES - Español
zh_TW - 繁體中文 supported since Tableau Prep 2019.2
en_GB - English (UK) supported since Tableau Prep 2019.2


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