Here are some possible options (see attached data flow).
From the example in the spreadsheet it looks like a simple aggregation is required rather than using the Pivot Table node.

So, assuming this is the input data

A legacy Filter(Superseded) node would be configured to build the date string in DD/MM/YYYY format.

The configuration would be:

(the fields a, b, c are not required to be output - they are only there for debug purposes). The output of the node is:

The Pivot Table node would then be configured as follows:

Which results in the following output:

Alternatively, an Aggregate node would provide the data you indicated in your spreadsheet:


You could also use a Modify Fields node to convert the original data to a Date type and change its name to "Date".

You can then use the data with a Pivot Table node as before, or use an Aggregate node to sum the data and another Modify Fields node to convert the Date field to a string with a format of dd/MM/yyyy for publishing.

Attached files
Pivoted_Dates - 28 Jan 2021.lna