Insert date form footnote in Impress

I created a presentation and also defined a fixed date for the footer, that is the date the presentation will be hold on. Now I would like to reference this date on some slides. Of course, I could every time type the date manually. But I will definitely reuse major part of this presentation, so I would need to change the date on every place it is mentioned, again manually. Which is actually source of errors…

I tried to use the date field hoping it will solve my issue. But this field only displays the current date (if variable) or the date this field was created (if fixed) with no possibility to adjust the content.

So, is it possible to define the date variable using it then in the footer and on the slides? Or, at least, defining the date on two places: footer date and on-slide date (it is still much better than changing date on 6 different places)?