If you are using a CV to apply for a job in the United States, due to current laws regarding age discrimination, you do not need to include your date of birth on your curriculum vitae.
In fact, if you are posting your curriculum vitae online or are at all concerned about the validity of the company to which you are mailing your CV, it is best to omit your date of birth. This information can be used in identity theft scams.
However, be aware that a number of countries outside the United States expect you to include your date of birth on your CV. If you are applying to a foreign job, research the particular country’s protocol for job applications.