Ok. Then I assume, that you do not have a master calendar. In other words you will only see dates in your dashboard where you had sales.
What you need to do in that case, is to "flag" transaction dates in your transaction table where there was a promotion, because when you do that you can make them visualized in a different color on the dashboard after the load is completed.
My recomendation would be to create a flag based on those promotion dates in your load script with a mapping table inside your transaction table.
So, your mapping table should contain only the promotion dates. When mapped on the transaction table on the transaction date they should give a new field the value 1. If not matched, the transaction date should give the value 0, name this new field "Promotion date"
Then in your visualization you are able to have differen color depending on this field, using set analysis. If you need more help, I can do an example, and if you share your script, my example could be based on your table structure.
Though, this is just one solution. There are many ways to do it, more complec and more simple, depending on your demands. Another solution for instance would be to do it completely in the interface in your expressions.
But in the end, the best solution is depending on how structured the promotion dates are. In case they are always the same days every month, or same days every week, etc, there would be even easier solutions.
Robert
Svebeck Consulting AB
