Sounds scary, but yes that is how it works. Each Tikker watch comes with a questionnaire booklet called "About Time". You will fill out this questionnaire about your health history and subtract by your age from the result then "boom!" Your time starts ticking.
Why you should wear one?
According to Mashable, Tikker aims to make people avoid wasting time in their lives. The creator of Tikker, Fredrik Colting, was inspired to create Tikker after his grandfather died. He emphasized the positive side of knowing how much time one has left to live.
Tick tock...