* Level of education: A kindergarten teacher's schedule is different from a university professor's. Kindergarten is typically a full academic year, while university semesters or quarters are shorter.
* Educational system: School years are different lengths in different countries. Some countries have longer school years than others, and the academic calendar may also vary.
* Type of institution: Public schools, private schools, and charter schools may have slightly different schedules.
* Specific course or program: A single course might last a semester, a quarter, or even just a few weeks, whereas a degree program could span several years.
Therefore, there's no single answer to the "period of teaching." It could be a semester, a year, several years (for a degree program), or even a lifetime for a career educator.