They're trying to maximize sales and revenue, etc, for the quarterly report. An order that slips two weeks at the start of the quarter won't reduce sales, but orders that slip over the line at the end of the quarter would. Same with geography. An order that rolls off the assembly line on 15 September probably won't be sold by EOQ if it's going to Miami, but if it's going to LA it can. So they concentrate on long range orders early and short range ones late. this doesn't apply to Fremont, but Shanghai units are almost all exported at the beginning of the quarter but at the end they're all domestic (to China).