$template->param(months => [{monthname=>'January'},
                            {monthname=>'Febuary'},
...                         {monthname=>'December'}]);

$template->param(personnel => [{name=>'Bottum',
                                workinghours =>[{hours=>aaa},
              {hours=>aaa},
...],
total => bbb},
                        {name=>'Bottum',
                                workinghours =>[{hours=>aaa},
              {hours=>aaa},
...],
total => bbb},
]);