Are commercial foods adjusted for integer cooking times?
No. Pasta certainly can be varied by 1-2 minutes depending on the degree of bite desired (assuming the commercial, dried variety). Furthermore, height above sealevel determines air pressure and the boiling temperature of water, which further complicates things.

For microwaving, a similar problem occurs with power: not all microwaves have the same effective power, which means that you can't have an integer number of minutes of cooking time. In fact, if you see 600 W : 8 minutes, 1000 W : 5 minutes, you already know that they're rounded numbers (600*8 = 4800; 1000*5 = 5000, ignoring the larger heat loss in the first case)

[edit]
A bit of math on the back of a napkin suggests that even at a fixed altitude, the difference between high and low air pressure is significant enough. No, they're not adjusting the ingredients to come up with an integer number. Besides, it'd be far easier to vary the thickness a bit.