Before starting the dishwasher turn your hot water faucet on until the water is super hot, then start your dishwasher (and turn your faucet off). This will fill your dishwasher with hot water instead of cool because you have pulled the hot water to the kitchen thru the faucet first.

It takes a dishwasher 1-1.5 minutes to raise the temperature of water 1 degree. So if you fill the washer without running the hot faucet first you are filling it with cool, 60-ish degree water. It can take a good hour and a half for the washer to raise the water temp to 120 degrees (which it should be to wash dishes properly). Therefore your dishwasher is working an extra hour or more to raise the temp of the water before it even starts to "wash" the dishes.

Is your dishwasher cycle long, even on the "economy/short" cycle? Then above may be the answer. Pretty simple fix, huh!