Cooldown Start time after System Reset

[Nu7a]

Alright, so I am trying to make some cooldown timers, however I have ran into a problem when the system resets. The cooldown displayed by my addon goes berserk. I know why this is, it is because GetTime() is based off of system time of the client. However what I find odd is that this is no problem from blizzard's end. So after talking to tuller, he pointed me in a great direction. Apparently the new start time they give the cooldown is based around something, and that I should use time() with some sort of epoch to figure out the cooldown remaining. Alright, its all fine and dandy. Set the epoch to some time during July 20, 2010 (24 hour serv maintenance) , did some tweaks with the time to get it in-line with wow. However when I reset the system again, the time is off again. What I discovered is that the start time keeps changing. I would get 4289526.471 then restart and get 4289412.817, so it decreases. Anyone have an Idea how this value is actually calculated??