Puzzle #165: Date Puzzle

Consider a date in YYYY-MM-DD format. What is the next date where all eight digits will be different?

Submit your answer to Gene Wirchenko <genew@telus.net>. Your answer should be in the form of a proof. That means to show how your answer must be correct. The deadline is Wednesday, August 3, 2016 at noon Pacific Time. I will post the answer shortly after.