The length of time to graduate from culinary school depends on the school and the type of degree, but can vary from 21 months for an associates degree up to 36 months to get both an associate's and a bachelor's degree. These courses, depending on the school you attend, may or may not include pastry and applied food studies.
Some professional cooking schools offer smaller programs as well, for those that have some experience or want to learn for personal use instead of professional. These courses can take anywhere from weeks to months depending on what is involved and the school offering the programs. Most of the programs, even the certificate and diploma programs are addable to a resume.