is it new function block with the old Function node N8N

function.js

const staticData = getWorkflowStaticData('global');
const newRSSIds = items.map(item => item.json["Date"]);
const oldRSSIds = staticData.oldRSSIds; 

if (!oldRSSIds) {
  staticData.oldRSSIds = newRSSIds;
  return items;
}


const actualNewRSSIds = newRSSIds.filter((id) => !oldRSSIds.includes(id));
const actualNewRSS = items.filter((data) => actualNewRSSIds.includes(data.json['Date']));
staticData.oldRSSIds = [...actualNewRSSIds, ...oldRSSIds];

return actualNewRSS;