I want to calculate age when date is selected by using jquery date picker. I added code below but it showing minus value if i select date like '19/03/2015','15/01/2015' or '19/03/2014' ,'31/12/2014'

  $(document).ready(function () 
{
 console.log($(document).width());           
     $('#patientDob').datepicker
    ({
        dateFormat: 'dd/mm/yy',
        changeMonth: true,
        changeYear: true,
        yearRange: '1900:2150',
        maxDate: new Date(),
        inline: true,

             onSelect: function() {
               var birthDay = document.getElementById("patientDob").value;
                var DOB = new Date(birthDay);
                var today = new Date();
                var age = today.getTime() - DOB.getTime();
                age = Math.floor(age / (1000 * 60 * 60 * 24 * 365.25));

                document.getElementById('patientAge').value = age;
            }
     });  

});

I want to calculate age when date is selected by using jquery date picker. I added code below but it showing minus value if i select date like '19/03/2015','15/01/2015' or '19/03/2014' ,'31/12/2014'

  $(document).ready(function () 
{
 console.log($(document).width());           
     $('#patientDob').datepicker
    ({
        dateFormat: 'dd/mm/yy',
        changeMonth: true,
        changeYear: true,
        yearRange: '1900:2150',
        maxDate: new Date(),
        inline: true,

             onSelect: function() {
               var birthDay = document.getElementById("patientDob").value;
                var DOB = new Date(birthDay);
                var today = new Date();
                var age = today.getTime() - DOB.getTime();
                age = Math.floor(age / (1000 * 60 * 60 * 24 * 365.25));

                document.getElementById('patientAge').value = age;
            }
     });  

});

• javascript
• jquery
• html
• datepicker

• What do you mean "it showing minus value"? – zozo Commented Mar 19, 2015 at 5:29
• I seriously doubt that the only age problem is the minus value. For example new Date("31/12/2014") = 12 Jul 2016 ... read the answer (edited, had a problem last time) :). – zozo Commented Mar 19, 2015 at 5:52

2 Answers 2

I have created this age calculator for my project using jQuery UI. and JavaScript function. you will get the exact result.

It it will calculate age and display as human readable. create a date field with ID 'datepicker'and import jquery and jquery ui . After that

Then just copy and paste the code to get the exact result.

output // 28 years 7 months 7 days

        $(function () {
        $("#datepicker").datepicker({
            changeMonth: true,
            changeYear: true,
            showAnim: 'slideDown',
            dateFormat: 'yy-mm-dd'
        }).on('change', function () {
            var age = getAge(this);
           /* $('#age').val(age);*/
            console.log(age);
            alert(age);

        });

        function getAge(dateVal) {
            var
                birthday = new Date(dateVal.value),
                today = new Date(),
                ageInMilliseconds = new Date(today - birthday),
                years = ageInMilliseconds / (24 * 60 * 60 * 1000 * 365.25 ),
                months = 12 * (years % 1),
                days = Math.floor(30 * (months % 1));
            return Math.floor(years) + ' years ' + Math.floor(months) + ' months ' + days + ' days';

        }

});

AFAIK The javascript Date requires yyyy/mm/dd, and you are sending:

 var DOB = new Date(birthDay); //  dateFormat: 'dd/mm/yy'

Change format to "yyyy/mm/dd" and will work ok.