Does Swift Cast work on any skills?

[VanilleFang]

snip

I don't really understand how you can say you take x amount of damage every y seconds when the mobs attack every 2.5 seconds, not every second. If you take damage every 2.5 seconds wouldn't the total amount of damage you take every 3 seconds be the same as the total damage you take every 4 seconds (up to a point)? Or am I just not understanding something here?