String leaveTime="";
SimpleDateFormat sDateFormat=new SimpleDateFormat("YYYY-MM-dd HH:mm:ss");
Date date=new Date();
leaveTime=sDateFormat.format(date);

<script type="text/javascript">
      $().ready(function(){
          var tDate=new Date();
          var year=tDate.getFullYear();
          var month=tDate.getMonth()+1;
          var day=tDate.getDate();
          var hour=tDate.getHours();
          var minute=tDate.getMinutes();
          var second=tDate.getSeconds();
          if(month<10){
              month="0"+month;
          }
          if(day<10){
              day="0"+day;
          }
          if(hour<10){
              hour="0"+hour;
          }
          if(minute<10){
              minute="0"+minute;
          }
          if(second<10){
              second="0"+second;
          }
          $("#leaveTime").val(year+"-"+month+"-"+day+" "+hour+":"+minute+":"+second);
      });
  </script>