In python create function using current date to calculate End of the Current month.

The below link may be useful to Create function in python report file and call in Openoffice

https://accounts.openerp.com/forum/Help-1/question/24462

report \attendance_errors.py

def __init__(self, cr, uid, name, context):
    super(attendance_print, self).__init__(cr, uid, name, context=context)
    self.localcontext.update({
        'time': time,
        'lst': self._lst,
        'total': self._lst_total,
        'get_employees':self._get_employees,
    })

def _get_employees(self, emp_ids):
    emp_obj_list = self.pool.get('hr.employee').browse(self.cr, self.uid, emp_ids)
    return emp_obj_list

report \attendance_errors.sxw file open with openoffice

[[ repeatIn(get_employees(data['form']['emp_ids']),'employee') ]]