why don’t you load the data straight from the spreadsheet?
You can either use the https://flows.nodered.org/node/node-red-contrib-spreadsheet-in to load excel workbooks directly or you save it as an csv and use the inbuild nodes for it. No reason to go via the dashboard.
to convert hh,mm to hh:mm:
const msgformat = msg.payload.replace(/\,/g,":");
msg.payload = msgformat;
return msg;
this uses the replace method https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace and a regex to search for an , and replace it with a :
Johannes
Edit: Can you give as an example on what the data in the spreadsheet looks like? This would make this a whole lot easier?
Edit2: You can even load directly from a google spreadsheet: Google Spreasheet zu Node Red
