Well, I have a little too much time on hand tonite, so I studied the CO timetable a little on what CO's 18 777 will be doing from Apr 02/03. This doesn't take into account the new PEK authority.

I will use a particular time, midnight EST or CST, and see where the planes are. [I know that HKG is only flown 6 times a week, and one of the TLV flights 5 times, but I'm ignoring those missing frequencies to make it simpler.]

2 enroute IAH->LGW
1 enroute each IAH->NRT & CDG

2 enroute EWR->TLV
1 enroute each EWR->AMS, FRA, HKG, LGW, MAD, CDG, NRT

1 enroute TLV->EWR
1 on ground, or about to depart HKG->EWR

2 overnighting in IAH

That accounts for 17 of the 18 birds. I assume one of them may be in heavy maintanence at any time point, or overnighting in EWR.

Of those 17 in rotation, there are really little downtime. One stays on the ground in HKG for ~16 hours, one in TLV for about 7 hours, and two at IAH for about 18 hours each. That's all.