Date formatting / grouping

Hi,

I am using a excel data source (Excel with a dynamic data source, disabling the possibility to edit to much on the excel side).

As can be seen from the attached picture the data source is only indicating date in top row of each group ie. January has 5 data inputs, February the same and so on.

What I would like to do is somehow create a relation between the date and the data group (Date_1 and Area) either by duplicating the date on each row or somehow group it.

Any idea how this can be done?