Perhaps the most boring time-travel movie I've ever seen. Two engineers, who always are wearing white shirts and ties no matter what time of day, invent a device that is able to take them back in time. The majority of the time is spent experimenting by going a day back in time and not really doing anything interesting other than betting on the stock market. The movie gets a hair more involving when they decide to stop a guy who shows up at a party with a shotgun. PRIMER is a yawner.