@Savi I think you only need one date format in your nifi expression language. Next, it seems you know what format it is upstream (source), and what it needs to be for downstream. Based on your expression need, you should play the flow up to the csv reader processor and then List Queue on the FlowFiles and inspect the attributes. Adjust the expression, and retest until the attribute format meets the required format. Inspecting the dates upstream won't show you what the date looks like after expression and before the reader. Often times I find myself testing a flow step by step, each step confirming the attributes needed are correct for the next step. Never moving forward to the next step until I am sure the attributes are correct after visual inspection.
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