The moment that a recruiter or employer reads a resume and sees that the date is missing from the year that the candidate graduated from college, we realize that it means one of three things –
1) You are young, have likely had an accelerated career and are trying to hide your age.
2) You are quite experienced and have likely left off some of your earlier jobs from your resume in order to appear less experienced than you are
3) You didn’t complete your college degree.
It is a warning bell for the person reading your resume, and the result is that we analyze it in MUCH more detail than we would have had you simply left the year on.