According to a recent publication by the Food and Agricultural Organization of the United Nations...
"In most varieties the sugar content of the date fruit is almost entirely of the inverted form (namely glucose or fructose}. Important for persons who can not tolerate sucrose. The invert sugar in dates is immediately absorbed by the human body without being subject to the digestion that ordinary sugar goes through. Their energy is in the form of invert sugars, except for the Deglet Noor and Thoory varieties, in which about one-half of the sugar content is in the form of cane sugar or sucrose."