This comes under the "and more" section of this subforum's description. These fruits are featured now at my local green grocer, labelled as "jujubee dates", from China. It turns out that they are not really dates at all, are in the Rhamnaceae family, botanical name Ziziphus jujuba, common name jujube, see Wikipedia - Jujube - Wikipedia. They look like crab apples but are surprisingly light in weight. They are crunchy and juicy and seem like impossibly sweet apples. I had to eat all the flesh off the pit to convince myself that I wasn't eating an apple. The Wikipedia article mentions that the trees grown in California are different, but it doesn't say what they are. Here is another page that lists several cultivars: JUJUBE Fruit Facts. I have also learned on this page that "The fully mature fruit is entirely red. Shortly after becoming fully red, the fruit begins to soften and wrinkle. The fruit can be eaten after it becomes wrinkled, but most people prefer them during the interval between the yellow-green stage and the full red stage." They can be dried without the use of a preservative.
I tried a fresh one some years ago, a store sample, and it was tasteless. It must not have been ripe since the ones I just had were really sweet. It seems I've had them before as candied dried fruit when I was young. Now I know what they were.