TW scheduled all their West Coast redeyes to connect to the bank of eastbound flights departing ~0700-0730; the first arrivals from the east coast (and places like DTW/CMH/DAY/SDF/IND/CHI and Florida) blocked in ~0745-0815 to enable passengers to get to LAX/SAN/SFO/LAS/PHX/ONT/SEA by noon
I was on the SEA-STL redeye Thurs before Memorial Day weekend of 1979, connecting to DCA; returned on Tues evening