function respondeToDailyTrigger(){
  var now = new Date(); // Similar to Google Sheets NOW();
  var jsMonth = now.getMonth(); // 0 for January, 1 for February, and so on
  var spreadsheet = SpreadsheetApp.getActive();
  var sheet = spreadsheet.getSheetByName('Sheet1');
  var range = sheet.getRange('A1'); // destination cell
  range.setValue(jsMonth + 1);
}