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

Input:
Question: Can you set a start time? Leave home and have it come on by itself.
Document: Works very well. The only thing I am disappointed about is that although it is described as "programable" you can not set a start time. In other words, if you want it to come on at 10 AM and you leave for work at 8 AM you are out of luck.
I needed a smaller unit.After agonizing about multiple choices, I chose to go with truly modern features. What I have come to like the best is being able to set a specific time and having it automatically move to warm until I am ready to serve. This really came in handy a few days ago when my husband and I were delayed 2 hours getting home.I have read criticisms about the temperatures being too high.
I gave this machine 5 stars but I would like to give Amazon no stars for the machine. I love the timer setting feature - so I can set the timer and then it switches to warm when the timer is up, so I can come home after work with it ready to eat!! However, my machine had two large dents. Not sure if this is Amazon's fault or whoever their supplier is gave them a bad batch of machines?
I love this thing! The timer works great, and my food has never been dried out by the time I got home thanks to the physics of slow cookers (I was terrified of that before buying and wasted alot of time looking for one that had a delayed start instead. If that's you, just buy this!). I took it to an event at church recently, and people RAVED about how good it looked too! I coulnd't be happier.
The three cooking levels (high, low, and simmer) plus "keep warm" are a nice feature.The book tells you what the temperatures the settings maintain. I like that it will start on "high" no matter what you set it for until it comes up to temperature and then shift to your setting. (Heating quickly past the "Danger Zone") When your cooking time is up, it will shift to "keep warm".
I wanted a smaller crockpot that was programmable, and this one turned out to be a very good choice. I was looking for a small crockpot that would shift itself down to a low temperature as I am at work at least 9-1/2 hours with travel time, and I can't come home to turn it on or down. This fits the bill nicely. I am very happy with it.
I'll start with the positive. First it's Cuisinart and I have never had a complaint with any Cuisinart product that I own. I love that this slow cooker is programmable. It cooks evenly and you can set it to shut-off from cooking to Keep Warm. The one downfall is that I didn't realize how small the crock itself was. I've had a difficult time fitting a couple things in. It looks slightly oval in the picture but it's a round crock.
I use this all the time. I wouldn't buy a slow cooker without the warming feature this one has, i.e., after the food is done cooking, the slow cooker keeps it warm, which is useful if you are out and won't return home when it is done. Besides soup, I use it to cook hulled barley. Choice of low or high settings, and you can set the number of hours you want.
Great little slow cooker/crockpot.The unit cooks well and evenly.The sleek design is suitable for a permanent home on the counter (unlike my older crockpot with it's 1970's floral print, which is best hidden in the cupboard). The retractable cord is an added bonus that makes it easy to keep on the counter or store neatly on a shelf.The digital display is great - I love being able to set the time and walk away.
A few reviewers have lamented the lack of a delayed start program, but a feature that encourages you to leave raw food at room temperature for a prolonged period did not sound that desirable to me. The cooker will automatically switch to a safe warming mode in case you are not around at the end of the cooking cycle.A cookbook is included, but most of the recipes are one or two steps beyond the convenience of a mix-and-go meal.
Answer: The reason slow cookers don't have start timers is it wouldn't be safe to leave raw ingredients out at room temp for anything longer than prep time.  You don't want bacteria growing in your food before you begin ooking.