JSFiddle - React, Tailwind, and code Playground

HTML

<input onKeyUp="checkdate();" type='text' name="text1" placeholder='dd/mm/yyyy' id='returning_date'>

<span id='error8' style='color:red;'>format</span> <br><Br>

JavaScript

function checkdate(){
	//var sendDate = document.getElementById('send_year').value + '/' + document.getElementById('send_month').value + '/' + document.getElementById('send_day').value;
	var sendDate = document.getElementById('returning_date').value;
	



	
	
	sendDate = new Date(Date.parse(sendDate.replace(/-/g,' ')))
	today = new Date();
	today.setHours(0,0,0,0)
	if (sendDate < today) {
		//alert('The  date can\'t be in the past. Please pick another date.');
		
		document.getElementById('error8').innerHTML = 'The  date can\'t be in the past. Please pick another date.';
		return false;
	}
	else
{
   document.getElementById('error8').innerHTML = '';
}




}