Can an employer establish bona fide measures to ensure employees' regular attendance?

18 Insofar as the operation of an enterprise relies on its workforce, there is no doubt that an employer may establish bona fide measures to ensure employees’ regular attendance. For example, an employer’s right to require that employees work on certain days of the week was recognized in Ontario Human Rights Commission v. Simpsons‑Sears Ltd., 1985 CanLII 18 (SCC), [1985] 2 S.C.R. 536 (“O’Malley”), at pp. 555‑56, and in Central Alberta Dairy Pool, at p. 520. Similarly, it must be recognized that parties to a collective agreement have a right to negotiate clauses to ensure that sick employees return to work within a reasonable period of time. If this valid objective is recognized, the establishment of a maximum period of time for absences is thus a form of negotiated accommodation.