53.17. For the purposes of sections 50.3, 57 and the sections that refer to section 57, the contributory period of an employee who during a year holds pensionable employment under the plan for which the basis of remuneration is 260 days is determined by dividing by 260 the number of contributory days comprised in the period during which the employee was a member of the plan or comprised in the period for which days and parts of a day were otherwise credited to the employee with contributions for that year under the plan, within the meaning of section 73, except the days and parts of a day determined by regulation, during the pensionable salary reference period for the year established in accordance with section 37.1.
The contributory period of an employee who during a year holds pensionable employment under the plan for which the basis of remuneration is 200 days is determined by dividing by 200 the number of contributory days in the school calendars included in the period during which the employee was a member of the plan during the two parts of a school year included in a calendar year or in the period for which days and parts of a day were otherwise credited to the employee with contributions, for that year, within the meaning of section 73, except the days and parts of a day determined by regulation.
The contributory period of a new employee for the year during which the employee becomes a member of the plan begins on the first day in respect of which the employee paid or was exempt from contributions and the last period ends on the last day credited in the year during which the employee ceases to be a member of the plan.
In the case of an employee to whom section 25.1 applies and who holds pensionable employment for which the basis of remuneration is 260 days, a contributory period that corresponds to the pensionable salary for the year for which no service is credited is also determined by dividing by 260 the number of contributory days referred to in the first paragraph that correspond to that salary.