Yes, provided you pay them call-in pay. In Ontario, call-in pay rules are set out in ESA Sec. 21.2, which I’ve pasted below. Just go thru each part of the Section and see if it applies to your situation, e.g., Do workers regularly work more than 3 hours per day, are they required to be present at work, etc.
Three hour rule
21.2 (1) If an employee who regularly works more than three hours a day is required to present himself or herself for work but works less than three hours, despite being available to work longer, the employer shall pay the employee wages for three hours, equal to the greater of the following:
1. The sum of,
i. the amount the employee earned for the time worked, and
ii. wages equal to the employee’s regular rate for the remainder of the time.
2. Wages equal to the employee’s regular rate for three hours of work. 2018, c. 14, Sched. 1, s. 5.
Exception
(2) Subsection (1) does not apply if the employer is unable to provide work for the employee because of fire, lightning, power failure, storms or similar causes beyond the employer’s control that result in the stopping of work. 2018, c. 14, Sched. 1, s. 5.
Hope that helps. Glenn