I've been wondering for awhile how the nitty-gritty of cooldown rate boosters/debuffs work. Ordinarily I would simply assume they reduce the cooldown times of abilities used during the effect by the appropriate percentage.

But many of the info cards say things like Increased cooldown "rate"

So my question is this: suppose we have a 100 second cooldown ability that gets used while under the effect of a +25% ability cooldown reduction rate buff that has 20 seconds left in it's effect.

1). Is the ability cooldown set straight to 80 seconds at the time of ability use(as per standard sins presentations of percentiles as inverses).  This is to say in this case the only point in which the cooldown rate buff/debuff matters is the moment in which an ability is cast

or

2). Does the cooldown timer simply tick faster for the 20 seconds left on the buff, resulting in the total cooldown being 95 seconds(5 seconds shaved off by 20 seconds of +25% cooldown rate)

This distinction has some pretty significant strategic implications.  As I said, I would normally have assumed #1, but the inclusion of the word "rate" really makes me wonder.

Anyone know for sure?