I typically fly JFK-LAX at least once a month on a saturday morning and return sunday morning. On the JFK-LAX route, my Delta One upgrades (if I get them), tend to clear around 1:30am-3am for a 7am departure. If I take the LAX-JFK redeye back on a saturday, upgrades tend to clear around 3pm, day of departure. If I depart on a sunday morning LAX-JFK, it usually clears 2am-3am day of departure. Of course this all depends on if there's many medallion members on my flights.