If it's not too late, I suggest you try to route via ICN instead of PEK because the connection experience is far nicer (e.g. no need to reclaim luggage or check in twice, much less walking, better lounges/shops). If you take an overnight flight on OZ (e.g. from ORD, LAX, SEA, etc), you can connect to OZ in the morning. Meanwhile, CA offers an evening flight that connects with daytime flights from the US.