3 quarts pure, unsweetened cranberry juice (if unavailable, use cranberry juice cocktail and omit the sugar called for)
2 cups sugar, or to taste
3 cups amber rum, if desired
Cut tangerines crosswise into 1/4-inch-thick rounds and remove seeds. Stud rind of each tangerine round with 4 or 5 cloves. In a large saucepan simmer cranberry juice, tangerine rounds, and sugar, covered, 5 minutes and stir in rum.
Serve toddies with clove-studded tangerine rounds in heatproof glasses.