JSFiddle - React, Tailwind, and code Playground

by lchau

HTML

<input type="datetime-local" id="date-picker"/>
<button>
  i do nothing
</button>

JavaScript

var date_picker = document.getElementById("date-picker");
date_picker.value = new Date().toISOString().slice(-4);

function getTimestamp(date) {
  var str = date.toISOString();
	return str.substr(0, str.lastIndexOf(":"));
}

function setDate(date) {
	date_picker.value = getTimestamp(date);
}

// set default date
setDate(new Date());

// validate date on blur
date_picker.addEventListener("blur", function(event) {
	var date = new Date();
  if (event.target.valueAsDate) {
  	date = new Date(Math.min(date.getTime(), Date.now()));
	}
  setDate(date);
});