TypeScript Code

This script gets the current date and time and then writes those values to two cells in the active worksheet.

function main(workbook: ExcelScript.Workbook) { 
  let date = new Date(Date.now()); 
  let dateRange = workbook.getActiveWorksheet().getRange("A1"); 
  dateRange.setValue(date.toLocaleDateString()); 
  let timeRange = workbook.getActiveWorksheet().getRange("B1"); 
  timeRange.setValue(date.toLocaleTimeString()); 
} 

This script reads a date from cell "A1" and translates it to a JavaScript Date object.
It uses the date's numeric serial number as input for the JavaScript Date.

function main(workbook: ExcelScript.Workbook) { 
  let dateRange = workbook.getActiveWorksheet().getRange("A1"); 

  let excelDateValue = dateRange.getValue() as number; 
  let javaScriptDate = new Date(Math.round((excelDateValue - 25569) * 86400 * 1000)); 
  console.log(javaScriptDate); 
}