Character Hacks New Button:
Cooldowns — Can be used to lower or increase cooldown timers.
Use the cooldown you want to reduce and then click the Cooldown button.
You will see the offset of that cooldown and its current cooldown timer on the right.
Double click on it, and it will move to the left side.
Double click on it on the left, and you can now input the reduction you want.
0.5 = 500 millisecond reduction.
It is possible, also, to increase the cooldown timer, which may be desirable if you are using the skill/spell speed hack on a job like MCH, by using a negative number.
-0.5 = 500 millisecond increase.
The "cap" on the reduction is based on your ping, and the server check is pretty strict, so don't expect to be able to go above 0.5. To delete a reduction, double right click on it.
This requires updating Speeder to the newest version.