TIBCO Spotfire does not recognize dates in the 'YYYYMMDD' format. Data in this format is interpreted as integers instead of dates.
There is currently no way to force the data to be imported in a date format.
A possible workaround is to create a new column (in date format) after the import.
Example (using the below data as an example):
ColA;ColB
20060724;A
20060831;B
1. Go to TIBCO Spotfire File menu > Open > File and select the data file
2. Change the data type during import for ColA to String (from Integer) and import
3. Then, after the data is opened, go to Insert menu > Calculated Column and enter the following expression:
Date(Concatenate(Left([ColA],4),"-",Mid([ColA],5,2),"-",Right([ColA],2)))
4. Then, click OK - now you have a date column based on the date string that was imported.