A large number of overseas private language schools hire teachers on an as-needed basis any time of the year. Sometimes, they are willing to hire you immediately to replace a teacher who has just left or who is about to complete their contract. Most of these contracts are for a minimum of one year. Oxford Seminars Job Placement Service has access to numerous job openings year-round and assists graduates in finding teaching positions every month of the year.
Private language schools, tend to hire in the late spring which is ideal for university students looking to work right away.
Government programs such as JET (Japan), EPIK (Korea) and NET SCHEME (Hong Kong) begin hiring many months before the academic year begins. Keep in mind that public schools, colleges, and universities generally begin terms in August/September and February/March.
For more information on peak hiring seasons in specific countries, visit Where You Can Teach and select a country.