// Create or parse a new date
let date = new Date();

// YYYY-MM-DD
let dateFormat1 = date.getFullYear() + '-' + ('0' + (date.getMonth() + 1)).slice(-2) + '-' + ('0' + date.getDate()).slice(-2);
// DD-MM-YYYY
let dateFormat2 = ('0' + date.getDate()).slice(-2) + '-' + ('0' + (date.getMonth() + 1)).slice(-2) + '-' + date.getFullYear();

// Log
console.log(dateFormat1);
console.log(dateFormat2);

// Parse a SQL date
let date2 = new Date('2015-03-04T00:00:00.000Z');

// YYYY-MM-DD
let dateFormat3 = date2.getFullYear() + '-' + ('0' + (date2.getMonth() + 1)).slice(-2) + '-' + ('0' + date2.getDate()).slice(-2);
// DD-MM-YYYY
let dateFormat4 = ('0' + date2.getDate()).slice(-2) + '-' + ('0' + (date2.getMonth() + 1)).slice(-2) + '-' + date2.getFullYear();

// Log
console.log(dateFormat3);
console.log(dateFormat4);