Date not shown in combined series on chart

That is my usage case. I can't format the date to a proper format, so it is not so damn long.
In the underlying questions, I can easily format the X column, so it will show the date just as I want. But, when I switch to table visualization, I'm not able to - neither when I combine them in a dashboard widget like that. Any ideia on how could it be done?

I ended up doing it on the same question. But I know it is not always possible, so this would be interesting to do (for instance, different databases).