I have a problem when blending two different sources, one is a cube connection and the other one is an excel file. Both have a list of dates that I want to blend to be able to display 3rd party conversions from the excel sheet along with the date and conversions from the cube data source. I've made sure to add date from the cube data source as a dimension on the shelf and I've tried manually editing the relationship between the two data sources. However, 3rd party conversions are still returned as null values and when adding the date from the excel sheet as a dimension this also returns a null value. Even though the symbol is there next to the date they don't seem to have blended properly and I'm suspecting it has something to do with the date format. I've played around with different date formats in the excel sheet before adding the connection in tableau but so far it has not made a difference. Has anybody got an idea what's wrong here? Attached are some screengrabs..