Providing reasonable defaults is a good user interface design guideline.Defaults both minimize the work required by users to enter data into software and explain the user interface by providing example values.
As the saying goes: even a stopped clock is correct twice a day.
However, before choosing the format of the placeholders, let’s look at the kind of errors users can make when entering expiry dates.
The data entry task is to accurately transcribe the month and year of the expiry date as printed on the card.
Although arbitrary, we may choose January because it’s the beginning of the year.
In contrast, we need to put more thought into the default year.