H1B Revoked - Grace period question

A “Revocation Notice Was Sent” by USCIS was sent on 7/28/2020, my employer noticed me on 8/18/2020 and I stopped work on that day. I have payroll till 8/17/2020.

Do I have 60-day grace period? Which date is the start day? Notice sent day or last working day?

Sorry to see this. You have to calculate from the notice sent day.