Note, the stardate is not ddmmyy. It is dmyy, where the day and month are one-digit or two digit numbers. So first May 2016 would not be 01 05 16, but 1 5 16. The tenth may would not be 10 05 16, but 10 5 16. Then you simply delete the space to make the date, so 1516 is 1st May 2016.
This is the most common error I see when people create the stardates.