There is no obligation for employers to allow employee's to call out from work at all: an employee can be written up, suffer discipline, or even be suspended or terminated for missing work. If an employer does allow an employee to call out sick without penalty, they can put their own rules or requirements on it--such as that documentation must be dated the same as the incidents for which the employee called out. The manager *could* dismiss the write-ups if he wants (and if the instructions from his own supervisors lets him) but he is not required to do so.