The quiet period begins when the registration stat

The quiet period begins when the registration statement is made effective and lasts for 40 days after the stock begins trading. Its purpose is to create a level playing field for all investors by ensuring everyone has access to the same information.

https://www.investopedia.com/terms/q/quietperiod.asp

However, a quiet period extends from the time a company files a registration statement with the SEC until SEC staff declare the registration statement "effective." During that period, the federal securities laws limit what information a company and related parties can release to the public.

https://www.sec.gov/fast-answers/answersquiethtm.html