Instruction: Generate an answer to the question by utilizing the information contained in the document.

Input:
Question: Does the color gradually change as the time passes, or is it that it will be fully green for a period of time and then suddenly be yellow?
Document: I have read reviews that this is a pain to set, but once you get the hang of it, you have it memorized. I only use the auto timer now (that sets like 80% time on green, 15% on yellow and 5% on red automatically), but can see the benefits of setting the manual timer for certain things (that sets each color to a specific amount of time that your child needs).
We were amazed at how quickly she came to understand how it works.It's a great visual and audible tool. I notice the kids looking up at the timer as it's going through its three color sequences - green to yellow to red - to see how much time is remaining. They get it!It's a bit cumbersome at first to set the time and preferences (minus one star), but after a while you get the hang of it.
I have 3 year old triplets and bought this timer when our bed time routine had become an hour long. I set each section to 5 minutes each and each of them get to pick each night what color they will be (green, yellow or red) and I lay down with each one for the 5 minutes while their color is lit up. And the rule is that when no color is lit up, then mommy has to go to bed too.
I love this little timer. We use it for time out, but you can use it for A LOT of stuff. You can set sound effects for when it changes color. You can determine how much time is at each color or set it on auto and just put in the total amount of time you want it to keep track of and it will stay green for 80% of the time, yellow for 19% of the time and red for 1% ... something like that.
I can look at the digital display and know exactly how much time is left. My daughter can see the green, yellow, and red lights, and know roughly where she stands. The flashes before the color changes and the programmable audible feedback are very helpful, too. It just gives a lot of different ways for us to understand how much time is left.The main drawback is that the controls are awkward. There is both a manual and an automatic mode, but they are both pretty similar.
The time tracker is good, once you know how to program it. You can program a standard setting, say you always give the child 15 minutes to play, you can set 12 minutes green and three minutes yellow and then red. You can have sounds between each segment or slience.If you change times frequently, you will either be frustrated by having to set it every time, or will become really good at doing it without the instructions.
Our 5-year-old son responds well to this timer and even reminds us to use it. Usual use in our house: morning routine for school, some meal times, and occasional time out periods. We often change the period of time on the manual timer, so we keep the mini-manual nearby to review reset and other commands. Remembering how to manipulate the timer is a challenge, but the guide is brief and easy to understand. We really love this timer.
I was very disappointed. I opened this after the 30 day return period. The battery compartment is sealed shut and the screw is stripped. Based on the other reviews there are a lot of people receiving a damaged item. Learning Resources should change manufacturers.
The first time I got this timer it worked for about three weeks. When it WAS working, it was great. The screen slowly dimmed so I thought it was the batteries even though it had only been three weeks. After replacing the batteries it would set but then when it turned to the yellow color it would light up all colors and stop. It would not compete one cycle without getting "stuck" on the yellow.
I purchased this item to use for time outs. It looks like a great idea. It takes 20 minutes of reading instructions before you can start it, then every time you want to use it, you have to push three buttons! When you're dealing with a stubborn 2 year old, who has had to be put in time out dozens of times, pushing 3 buttons every time is a real pain!To me the first color should be red, and the last color green, meaning time out over.
Answer: It is a sudden change at the time you specify.