Yeah, I've thought about the timers a bit too. I'm not sure how I feel about decreasing the allotted time with the passing of days. On the one hand, it gives you more grace in the beginning when you're learning how to operate and ramps up the difficulty in the later days when you should have a good grasp on the operation. However, I agree that in the later days it becomes very stressful trying to keep up.
I've been thinking it might be nice to have randomization built in to the timers. Some customers want things done quickly, others are more patient. The first few days could still be programmed to be very forgiving, but the later days' timers could range randomly from 45 seconds up to 120 seconds depending on the customers' moods.