How does the 72 hours RT-PCR time line work ? I know the 72 hour clock starts when you get your result back with your time you received the test result. Im flying wit Qatar Airlines leaving CMH, to OHARA ,DOH, then BKK . So my question is , do have be landing in BKK in 72 hours of my test result or leaving my last departure in DOH before my 72 hours is up ?