скрипт не работает в ie

 <table width="100%" cellspacing=0 cellpadding=0 border=0>
  <tr><td bgcolor="#f1f1f1">
 
<style>
#calendar2 {
  width: 100%;
  font: monospace;
  line-height: 1em;
  font-size: 13px;
border-collapse:collapse;
 
}
#calendar2 thead tr:last-child {
 
  color: rgb(255,0,0);
text-align:  center;
}
#calendar2 thead tr:nth-child(1) td:nth-child(2) {
  color: rgb(255,0,0);
  font-weight: bold;
text-align:  center;
}
#calendar2 thead tr:nth-child(1) td:nth-child(1):hover, #calendar2 thead tr:nth-child(1) td:nth-child(3):hover {
  cursor: pointer;
text-align:  center;
}
#calendar2 tbody td {
  color: rgb(34,97,38);
border: solid 1px forestgreen; 
text-align:  center;
}
#calendar2 tbody td:nth-child(n+6), #calendar2 .holiday {
 color: rgb(255,0,0);
border: solid 1px forestgreen;
text-align:  center;
}
#calendar2 tbody td.today {
  background: rgb(72,182,88);
  color: #fff;
border: solid 1px forestgreen;
text-align:  center;
}
</style>
 
<table id="calendar2">
  <thead>
    <tr><td> &larr; <td colspan="5"><td> &rarr;
    <tr><td>Пн<td>Вт<td>Ср<td>Чт<td>Пт<td>Сб<td>Вс
  <tbody>
</table>
 
<script>
function Calendar2(id, year, month) {
var Dlast = new Date(year,month+1,0).getDate(),
    D = new Date(year,month,Dlast),
    DNlast = new Date(D.getFullYear(),D.getMonth(),Dlast).getDay(),
    DNfirst = new Date(D.getFullYear(),D.getMonth(),1).getDay(),
    calendar = '<tr>',
    month=["Январь","Февраль","Март","Апрель","Май","Июнь","Июль","Август","Сентябрь","Октябрь","Ноябрь","Декабрь"];
if (DNfirst != 0) {
  for(var  i = 1; i < DNfirst; i++) calendar += '<td>';
}else{
  for(var  i = 0; i < 6; i++) calendar += '<td>';
}
for(var  i = 1; i <= Dlast; i++) {
  if (i == new Date().getDate() && D.getFullYear() == new Date().getFullYear() && D.getMonth() == new Date().getMonth()) {
    calendar += '<td class="today">' + i;
  }else{
    calendar += '<td>' + i;
  }
  if (new Date(D.getFullYear(),D.getMonth(),i).getDay() == 0) {
    calendar += '<tr>';
  }
}
for(var  i = DNlast; i < 7; i++) calendar += '<td>&nbsp;';
document.querySelector('#'+id+' tbody').innerHTML = calendar;
document.querySelector('#'+id+' thead td:nth-child(2)').innerHTML = month[D.getMonth()] +' '+ D.getFullYear();
document.querySelector('#'+id+' thead td:nth-child(2)').dataset.month = D.getMonth();
document.querySelector('#'+id+' thead td:nth-child(2)').dataset.year = D.getFullYear();
if (document.querySelectorAll('#'+id+' tbody tr').length < 6)   {  
}
}
Calendar2("calendar2", new Date().getFullYear(), new Date().getMonth());
document.querySelector('#calendar2 thead tr:nth-child(1) td:nth-child(1)').onclick = function() {
  Calendar2("calendar2", document.querySelector('#calendar2 thead td:nth-child(2)').dataset.year, parseFloat(document.querySelector('#calendar2 thead td:nth-child(2)').dataset.month)-1);
}
document.querySelector('#calendar2 thead tr:nth-child(1) td:nth-child(3)').onclick = function() {
  Calendar2("calendar2", document.querySelector('#calendar2 thead td:nth-child(2)').dataset.year, parseFloat(document.querySelector('#calendar2 thead td:nth-child(2)').dataset.month)+1);
}
</script>
 </table>