setInterval is not defined- Google Apps Script

Question

I am trying to run the following following script in Google Sheets, but I get: "ReferenceError: setInterval is not defined"

'function onEdit() {
var ss= SpreadsheetApp.getActiveSpreadsheet();
var range = ss.getActiveRange();
var sheet = range.getSheet();

// Check if the edited range is within A2:G5
if (range.getRow() >= 2 && range.getRow() <= 5 && range.getColumn() >= 1 && range.getColumn() <= 7) {
var now = new Date();
var end = new Date(now.getTime() + 10*1000); // 2 minutes from now

// Display the countdown in cell H1
//sheet.getRange("H1").setValue("Time Remaining: " + end.toString());
setInterval(function() {
  var remaining = (end - new Date()) / 1000;
  if (remaining <= 0) {
    clearInterval(intervalId);
    sheet.getRange("H1").setValue("Times up...");
  } else {
    sheet.getRange("H1").setValue("Time Remaining: " + Math.ceil(remaining) + " seconds");
  }
  }, 1000); // update the countdown every second
}
}`

I was expecting cell H1 to have a 10 second countdown from last cell edit, but nothing is displaying