The busiest day of the year for UPS and FedEx Corp. is this Thursday, Dec. 19, according to representatives from the two express carrier giants.

Called "Peak Day," UPS delivers more than 18 million packages on that day -- the equivalent of one package for every American child under the age of 5. It's about 210 packages delivered every second, and more than a 35% surge above UPS's average volume of 13.6 million packages a day.
FedEx Express handles more than 4.4 million packages on that day. This compares to average daily volume of about 3 million packages. FedEx Express and FedEx Ground expect to transport more than 6.6 million packages through their networks on the busiest day.
After Peak Day, packages will continue zipping through UPS's residential and commercial ground network through Dec. 24. Volume for UPS air express deliveries actually will crest on Christmas Eve -- Tuesday, Dec. 24 -- with a global volume of about 4.5 million air packages, more than double the normal average.
To accommodate the surge in volume, UPS has added some 60,000 seasonal helpers to its workforce of 360,000 and more than a dozen large jets to supplement the more than 600 aircraft in operation year-round.