sample: set today as default value to input type=date

by Riivr

HTML

<input type="date">

JavaScript

var now = new Date();
var y = now.getFullYear();
var m = now.getMonth() + 1;
var d = now.getDate();

//月と日は0埋めを行う
m = m < 10 ? "0" + m : m;
d = d < 10 ? "0" + d : d;

//yyyy-mm-dd形式
document.querySelector("input[type=date]").value = y + "-" + m + "-" + d;