EDIT: Figured it out. Used System.currentTimeMillis(). THANKS TO ALL THAT HELPED!
Thank you very much for your response. I think TESR is my way to go, but if I fail, I'll take your advice and just use textures. So is there an API way to animate? Or do I have to write a timer myself? The problem is that renderTileEntityAt is ran every tick for block existing in the world. So if I have two blocks then it will be ran 2 times per tick. I have something that I would like to turn on and off though. I want an animation similar to ComputerCraft's blinking placeholder. Any ideas?