When you use Power BI in direct query mode and load the columns of DATE and TIMESTAMP datatype, PowerBI will keep on loading (spinning) instead of fetching the data if there are any null values in the column.

To overcome this, a default date value is set to replace the null date from the version of BI Connector. 

Customizing Null Date Value:

Also you can customize the default date based on your need. To do so, kindly follow the below steps.

Step 1: Open “ODBC Administrator” and click on “Configure” button of the DSN created for connecting PowerBI with OBIEE. 

Step 2: Press Alt+V to open the advanced settings dialog box as shown below.

Step 3: By default "Enable Null date value (for PowerBI)" is selected and the default value will be set to "1/1/1900" as shown in the above image.

Step 4: You can use the date picker and select the required date.

Step 5: Now click OK and close BI Connector dialog box. 

This will help you to customize the null date value and it will be use to replace the null dates from OBIEE.

Now try loading the column and the null date or the empty date will be replaced with value specified through BI Connector settings.

NOTE: Don't disable this checkbox, when you have null value in the date column, resulting in loading the column data endlessly.