In a large bowl stir together sugar and pectin. Add the cherries, blueberries, and zest. Stir for 3 minutes.
Ladle jam into clean half-pint freezer containers, leaving a 1/2-inch headspace. Seal and label. Let stand at room temperature 30 minutes. Store in the freezer up to 1 year or in the refrigerator up to 3 weeks.