I'm quite anal about form validation. So while creating a validator for a "data of birth" (DOB) field in one of my current projects for a job application form (platform/language is neutral in this context), I wanted something to prevent 'punky' inputs.
I used a date picker and restricted the max date to be XX years from the current day. XX make sense for this scenario as anyone younger shouldn't be even applying for the job.
The validation error message is: You seem too young for the job.
Then I began to get adventurous. How about?
If DOB is more than 120 years ago, message: "You cannot be that old!!!"
If DOB is in the future, message: "You must be kidding, you are not born yet!!!"
In the end, I deployed without the last 2, too cheeky for my no-nonsense client.
I would like to know how far/much would you guys go to validate DOB fields for good usability (or humor)?
Similarly for dates like, "Date of marriage", "Year of graduation" etc...
PS: As I was about to submit this post, there's a warning under the title textbox: "The question you're asking appears subjective and is likely to be closed." Fingers crossed.
To add: I'm quite surprised that some/most of the guys are not too concern about the validation. I repeat one of my comments here:
If the user entered the date wrongly (something very obvious) whether by intent or by mistake; that's one of the purposes of the validators to catch it. When data goes into the system, the site owner only know the input is wrong, he/she would not know the actual value without asking the user. If this field is highly important, it will not be a pretty scenario.
Think about the times you've filled out forms. How many times have you been frustrated because some "overly clever" programmer inserted some "validation" that just happened to be incorrect for your circumstance? I say, trust the user. Come to think of it, as time goes on I guess people are living longer and getting on the net at earlier ages, anyway. :P