Ideally Anti rabies vaccine should be administered within 24 hrs of dog bite.  This is called post exposure prophylaxis. There is a pre exposure regimen as well , which means taking anti rabies vaccine before the Dog bite. According to this schedule, only 3 doses are to be administered.  But i haven't seen anyone yet taking this usually. Need of the Immunoglobulin depends upon the grade of exposure and not the time of bite.

As told to you earlier that vaccination is for preventing a disease and is not beneficial if there is an acute stage of disease