Remove the stones from the plums and chop. Crack a few of the stones and remove the kernels. Clean and grate the carrots, peel and finely chop or crush the garlic. Put the plums, kernels, carrots, garlic and vinegar in a pan and simmer until soft, about 50 minutes. Add the sugar, cayenne pepper, salt, ginger and chopped dates and boil for about 30 minutes or until thick. Pour into hot sterilized jars and seal.