While it generally takes four to six weeks to process a listing application, this time frame is variable and may be shortened considerably, if the application raises no issues and the company responds quickly to Staff comments.
Week 1. Company submits application for listing and Nasdaq Listing Qualifications Staff begins its review. Weeks 2-3. Staff completes its preliminary review and prepares comment letter. Weeks 3-4. Company addresses any issues raised by Staff. Weeks 5-6. Staff completes their review and company is approved for listing.
Additionally...
Public companies also enter into quiet periods during financings when securities (stock or bonds) are issued to the public.
There was a time in KBLB's history, where it took several months of communication, for the SEC to feel comfortable with granting The Company authorization.