Mix two cups of sugar with two cups of cold water. Pour over the cranberries and let stand for a day. Drain the cranberries in a colander for three minutes. Discard the strained juice. Mix the cranberries in a bowl with 3/4 cup of sugar. Cover with plastic and set aside.
Bring a pot of water to a simmer and set the bowl of cranberries over it. Let steep for two hours. Drain the cranberries, reserving the liquid. Reduce the liquid slowly over medium heat until it becomes a glossy syrup.
Mix one cup of water with one cup of sugar and bring to a boil. Place the tangerine segments in a bowl. Remove the mixture from heat and pour over the tangerine segments. Cool the segments in the refrigerator, then drain them and pat them dry. Stir the reduced cranberry syrup and the tangerine zest into the cranberries. Gently fold in the tangerine segments. Serve chilled.