按照规定，Must五天之内。超过五天，都not eligible

https://medical.mit.edu/covid-19-updates/2022/05/paxlovid

To be effective, treatment must begin within five days of symptom onset, so you are not eligible to take Paxlovid if you have had COVID-19 symptoms for more than five days.

How do I get Paxlovid?

Paxlovid is available at no cost by prescription only. If you have tested positive for COVID-19, are experiencing symptoms, and are at high risk for developing severe COVID-19 illness, you should obtain a prescription as soon as possible. It is important to act quickly, because you must begin taking Paxlovid within five days of your first symptom.