From revenues gained to revenues reported in a particular SEC form ~could be up to 3-5 months in a time period.
Think of payment terms (ex. Net 30/60/90), payment method (check, fund transfer, etc.) official SEC reporting quarters/periods, PCT accounting backlog (if any). There can be a few more things, but publicly traded companies (like the government in some ways- the worst BTW) can take a longer time to actually report earnings.
I think this 'time gap' actually gives fundamental investors an advantage over others when they do their solid due diligence and execute stock purchases or sells.