(Urgent) Need help on Perm Audit

[thesouravp]

in Perm audit , got inquiries to post the job posting on the wall of the office for 10 business days. Now we do have the pictures taken , now how to prove that those pictures are of which date? How to put date time stamp , in case we put that will the Office agree? How he will understand that the mentioned dates are proper?
Or can my company submit an affidavit saying they were really posted?
Appreciate your response.