Final answer:
Samuel must be allowed to take his statutory vacation time by October 31, 2019, as per Ontario's ESA rules, which grant a 10-month period after the end of the vacation entitlement year.
Step-by-step explanation:
Under Ontario's Employment Standards Act (ESA), employers are required to provide employees with vacation time after each 12-month vacation entitlement year. Since Samuel started work on January 1, 2018, his first vacation entitlement year would be completed on December 31, 2018. The ESA then provides a 10-month period following the completion of a vacation entitlement year for employers to grant this vacation time. Therefore, Samuel's employer is obligated to allow him to take his statutory vacation time before October 31, 2019, which is the end of the 10-month period following Samuel's first vacation entitlement year.