Help understanding secondary cells discharge curve
This is a graph of output voltage compared to state of charge at several discharge currents.  It's plotted against SOC because obviously we know it'll discharge faster if we pull more current--this type of plot allows us to more easily see how the rate of discharge affects the power actually delivered from a single charge.

If you want to translate it into time, you need to know the rated capacity, which is probably about 3000mAh.  That lets you scale 1C (3A) into a 1-hour time range.  The 2C (6A) version would be compressed by 2:1 on the same timescale, the 0.5C would be expanded by 2:1, etc.

Constant current discharge is typical, but in some cases you'll see resistive or constant power (emulating a switching regulator) curves too.