How to create a united date table from 3 different tables

Hi,

I have over 10 tables. Each of them contains several date fields. When making a report, to slice a visual based on one table I need to create as many date slicers as many tables with different date fields I used. 

Example: table A has created_date field; table B has arrival_date field. I want to see in one report that on 5th of December, for example, _n_users were created in table A and _z_users have arrived. But for now I need to create a time slicer with created_date from table A and a time slicer with arrival_date from table B. 

Is there any tip, trick, magic or an advice how can I unite those date columns? "Unite" function and creating a Calendar table didn't work for me. But 5th of December is 5th of December, anyway, and I would like, using a single date slicer, see all events happened at that day.

Any ideas?

Thank you in advance.

Kind regards,

T.