问题 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