You cannot carry on an expired CCW permit in Nevada. There is no grace period. The 60-day period refers to people moving in to Nevada carrying on their former state's permit. So once again, if your permit expires, you cannot on an expired permit. You must openly carry.
Should you choose to ignore the law, you better hope the cop is cool or the DA doesn't want to bother prosecuting. CCW without a permit is a FELONY.
The only possible exemption is for those whose permits expired on or after 3/12/2020 to 7/15/2020. Those permits were extended until 7/15/2020. No, there is no grace period or day count. Your expired permit is considered a temporary extension under existing authority until 7/15/2020. No, not 60 days after 7/15/2020, not 90 days after 7/15/2020. The grace period ends 7/15/2020.
So if your permit expired and you're waiting for an appointment to renew your permit and get a permit, you must openly carry in the interim. Don't worry, it's not a big deal in Nevada. This mainly affects those in Clark and Washoe Counties which are being deluged by applications delayed by the COVID-19 closures. Expect the 120 approval period to be the wait time after you submitted your application.
Don't like it? Vote out your sheriff in 2022 and vote Republican this November.