Originally Posted by synergypi

I don't think anyone really knows when additional seats get released; some evidence that clearing from waitlist can occur 2 weeks or so before the flight, and upgrades requests may clear around check-in. However, if there are premium members on the waitlist they will be cleared first so unlikely that general members can secure the seat(s).

Initial J seat release #s for general members leaving SFO seems to be 1 for Fri and Sat, 2 for Thurs and Sun, and 3 for Mon Tues Wed.
Initial J seat release #s for Pt or SFC members seems to be 2 for Fri and Sat, 4 for Sun-Thurs.