Happened a few times last year. The ones I remember off the top of my head were LAX-SLC on a CR9 on a Saturday morning, and several months later MSP-BDL, again on a Saturday morning. The LAX one cleared about 8 hours before we boarded (I was about to get on a plane from ANC-LAX which I got upgraded on at the FO window), and the BDL one was...I don't remember, but some time between checkin at t-24 and when I went to bed later that night.