How to get year and month of Bootstrap Datepicker as it on change

Get month:

 $("#datepicker").datepicker().on('changeMonth', function(e){ 
   var currMonth = new Date(e.date).getMonth() + 1;
 });

Get year

 $("#datepicker").datepicker().on('changeYear', function(e){ 
   var currYear = String(e.date).split(" ")[3];
 });