Recruitment Interviews - HOD's do not take interviews on time - delay it by 2-3 hours

Dear Recruiters, In my current company the HOD's do not take interviews on time and even they delay it by 2-3 hours and due to this the candidates got frustrated and this also give a very bad impression about the company. Kindly help me in drafting the policy or circular for adhering the interview discipline.
Thanking You
Prasoon Singh

Dear Prasoon,
Why don't you go and speak to the HODs regarding the brand image of the company/impression of candidates,which in turn shall serve your purpose.
If you are a HR or recruiter, there is no harm in paying a visit to them and discuss your problems with them for solutions,later when the things are still not in control then you can draft a circular to adhere.
Instead of a separate policy for interview discipline, you can frame a recruitment policy in general which can govern all the procedures.