<Dd> A trimester (Latin: trimestris, lit.' of three months') divides the academic year into three periods, separated by breaks . In some jurisdictions, trimester is used in its original meaning to indicate a quarter system (since three months is a quarter of a year), or a variation of it . </Dd> <Dd> A quarter is an academic term of about 12 weeks . An academic year divided into quarters allocates the same amount of time to summer term as to the autumn, winter, and spring terms . The terms quadmester and quadrimester are rarely used to describe a three - or four - term system . When US universities convert transfer credits between the semester / trimester and quarter systems, 36 quarter hours translate to 24 semester hours (based on a ​ ⁄ conversion factor); conversely, 36 semester hours translate to 54 quarter hours (based on a ​ ⁄ conversion factor). </Dd> <P> In most of Australia, the primary and secondary school year lasts approximately 200 days, from late January or early February to early or mid-December, and is split into four terms: </P> <Ul> <Li> Term 1 starts in late January or early February and ends in late March or early April (often in close proximity to Easter). </Li> <Li> Term 2 starts in late April or early May and ends in late June . </Li> <Li> Term 3 starts in mid-to - late July and ends mid-to - late September . </Li> <Li> Term 4 starts in mid-October and ends early to mid-December . </Li> </Ul>

When does the school year begin in australia