That's how long it would take to burn through AT&Ts 2GB data plan at the speeds they are now claiming for their LTE deployment:
Where Verizon's existing network promises download speeds of between 5 and 12 megabits per second (though we've gotten far better and worse in practice), the publication witnessed a connection with 28.87Mbps download and 10.4Mbps upload speeds, using a MIMO antenna passing bits through both 700MHz and AWS frequencies.
28.87Mbps = 3.6MBps
2048MB / 3.6MB = 569 seconds
569 seconds = 9.5 hours
9.5 hours of top speed downloading over 30 days = 20 minutes per day