JSFiddle - React, Tailwind, and code Playground

JavaScript

(function() {

	var resultA = [];
	var resultB = [];
	var resultC = [];
	var resultD = [];

	for(var run=0; run<4; run++) {



	var activities = [];
	var year = '';
	var month = '';
	var day = '';
	var date = '';

	
		for(var i=0; i<1000; i++) {

			day = Math.floor((Math.random()*31)+1);
			month = Math.floor((Math.random()*12)+1);
			year = "200" + Math.floor((Math.random()*3)+1);
			date = day + "-" + month + "-" + year   
			activities.push({ id : i, date : date });
		
		}

	for (var index in activities)
	{

		if (!activities[index].date)
		{
			activities[index].sortable = 0;
			continue;
		}
		var date = activities[index].date.split('-');
		activities[index].sortable = 10000 * parseInt(date[2]) + 100 * parseInt(date[0]) + parseInt(date[1]); 
	}

	activities.sort(function(a, b)
	{
		return a.sortable > b.sortable ? 1 : a.sortable < b.sortable ? -1 : 0;
	});

	var result = [];
	
		for (var index=0; index < activities.length; index++) {
		
			if(run == 0) {
				resultA.push(activities[index]);
			} else if(run == 1) {
				resultB.push(activities[index]);
			} else if(run == 2) {
				resultC.push(activities[index]);
			} else if(run == 3) {
				resultD.push(activities[index]);
			}
		}
	}


console.log(resultA);
console.log(resultB);
console.log(resultC);
console.log(resultD);

})();