@redmonc2   You should update the post with the input data, and a screen shot of your flow, for better responses from your peers.  If you provide this info I will update my response below.   Without being able to see the input data I believe you just need to adjust your flow so that you are breaking up the input data into multiple flowfiles.   For example, if that input data is lines of dates you want to change formats, your flow should split the lines with SplitText, then get each split FlowFiles date to an attribute called date (${date}) with ExtractText that uses regex to get the entire split content to the date attribute.  With an attribute called date in each flowfile,  you can then use your expression language in updateAttribute:   ${date:toDate("ddHHmm:ssMMMyy"):format("yyyy/MM/dd HH:mm:ss")}   Once you have the format correct for each date, you can proceed with the dates downstream as attributes or write them back to the content of the flowfile and merge them together.   If this answer resolves your issue or allows you to move forward, please choose to ACCEPT this solution and close this topic. If you have further dialogue on this topic please comment here or feel free to private message me. If you have new questions related to your Use Case please create separate topic and feel free to tag me in your post.     Thanks, Steven @ DFHZ ... View more