In an attributeCreator in the New Attribute you can put Days_$(param). It will be red in the input box, but the translation should run without issue. Note that since this is a dynamic attribute it won't be visible on the canvas for later transformers to use, but it will be on the feature.

@perry​ If you are trying to transpose data try the AttributeTransposer custom transformer from the FME HUB and look at the article: Transpose a Table Using FME for ideas.

If you have name/value pairs, you can use the same approach described by @jdh​  with attributes using the attribute creator. You can build up the name of the attribute in the AttributeCreator Text Editor.

Parameters are constant for the life of a workspace run, so you might not be able to get a list of dates that you show above.

Hi,

Indeed I was confused about the RED in the input-box and that the output was not visible in the canvas as mentioned by jdh.

I have tried a little test with

• Calculate the days (datetimecalculator) with result attribute DAYS
• then a attribute_creator and new_value <DAYS_@Evaluate($(JAAR_OUD)+@Value(T_TELLER)) > and value <DAYS>

My firts impression is that it seems to work good:

DAYS_2017 DAYS_2018 DAYS_2019

364 364

Tomorrow I will try to implement this in a loop.

(@Mark: I will surely investigate your tip Attribute Transposer.)

For now: thank you all for your support. 😊