I have a bottle of Tiki and one of Voodoo that are 2 and a half years old. Kept on a shelf out of direct sun. Tried the Voodoo about 2 months ago. Superb.
A quality juice, kept in dark glass, seems to last a long time. There might be some loss of nic strength, but that's ok here, as they are 12mg, way over my normal 6.