JSFiddle - React, Tailwind, and code Playground

JavaScript

var dob = "13-05-1981";
    mdob = moment(dob, 'DD-MM-YYYY'); // date of birth
    if (!mdob.isValid()) {
        alert("Invalid date format");
        return;
    }
    targetDate = moment(); //this will give today's date
    months = targetDate.diff(mdob, 'months');
    let years = parseInt(months / 12);
    let balanceMonths = months % 12;
    let days;
    if (!balanceMonths) {
        months = 0;
       // days = targetDate.diff(mdob, 'days');
        dob_date = mdob.date();
        target_month = targetDate.month();
       	construct_date = moment().month(target_month).date(dob_date);
    	days = targetDate.diff(construct_date, 'days');
        if(days < 0){
        	days = 30 + days;
        }
    } else {
        months = balanceMonths;
        dob_date = mdob.date();
        target_month = targetDate.month();
        construct_date = moment().month(target_month).date(dob_date);
        days = targetDate.diff(construct_date, 'days');
         if(days < 0){
        	
        	days = 30 + days;
        }
    }

    console.log("months", months)
    console.log("years", years)
    console.log("days", days)