[рони]

AnthonyFink,
пробуйте, и пишите в чём проблема?

newNote();
function saveToDo(){
	// take date of new note
	var date = new Date()
	// take note
	var getId = date.getTime();
	var getNote = document.getElementById('todobox').value;
	var futureDate = document.getElementById('future_date').value;
	var errorMessage = document.getElementById('error_message');
    errorMessage.classList.add("error_text");
	// validation for empty textarea

	if (getNote === "") {
		errorMessage.innerText = 'You must write something in description';
		errorMessage.classList.remove("error_text");
		document.getElementById('todobox').focus();
        return false;
        }else if(futureDate === ""){
        errorMessage.classList.add("error_text");
        errorMessage.innerText = 'You must write date';
        errorMessage.classList.remove("error_text");
        document.getElementById('future_date').focus();
        return false;
        }

   function validateDate(date) {
	            var str = date.trim().split("/");
    if (str.length == 3) {
        str = new Date(str[2], str[1] - 1, str[0], 0, 0, 0);
        if (str == 'Invalid Date') return false;
        str = [ ("0" + str.getDate()).substr(-2), ("0" + (str.getMonth() + 1)).substr(-2),str.getFullYear()].join("/");
        return str === date.trim()
    }
    return false

		 }
		 if (!validateDate(futureDate)) {
		 	errorMessage.innerText = 'You must write correct date'
	         errorMessage.classList.remove("error_text");
	         return false;
		 }
	var toDo = {id: getId, toDo: getNote, date: futureDate}
if (localStorage.getItem('todolist') == null){
	var to_do_list = [];
	to_do_list.push(toDo);
	localStorage.setItem('todolist', JSON.stringify(to_do_list));
}
else{
var to_do_list = JSON.parse(localStorage.getItem('todolist'));
	to_do_list.push(toDo);
	localStorage.setItem('todolist', JSON.stringify(to_do_list));
	}
 document.getElementById('todolist').reset();
 newNote();
}
// save note
function newNote(){
var newNoteList = JSON.parse(localStorage.getItem('todolist'))||[];
noteboard.innerHTML = '';
for(var i = 0; i <newNoteList.length; i++){
	var id = newNoteList[i].id;
	var toDoText = newNoteList[i].toDo;
	var myDate = new Date(id).toLocaleString();
	noteboard.innerHTML += '<div class="col-md-2 delete">' + '<span class="remove" onclick="deleteToDo(\''+id+'\')">'+ '<i class="far fa-trash-alt"></i>'+'</span>' +'<div id="text">'+ toDoText +'</div>'+ '<span class="date">'+ myDate +'</span>'+'</div>';
}
}

// delete notes
function deleteToDo(id){
var delete_to_do = JSON.parse(localStorage.getItem('todolist'));
for (var i = 0; i < delete_to_do.length; i++) {
	if (delete_to_do[i].id == id){
		delete_to_do.splice(i,1);
	}
}localStorage.setItem('todolist', JSON.stringify(delete_to_do));
		newNote();

}