Final answer:
The context provided refers to historical labor practices rather than the use of restraints on minors. Modern laws highly regulate or prohibit non-medical restraints on children, and the guidelines fall under child welfare and safety regulations.
Step-by-step explanation:
The question regarding the time limits for keeping restraints on a 9-17-year-old seems to be related to labor laws or child welfare regulations. However, the provided information and context refer to historical labor practices and do not directly relate to the use of physical restraints on minors. When about modern law or standards of care, the use of restraints on children for non-medical reasons is highly regulated, if not entirely prohibited. It's critical to make a distinction between labor regulations and the guidelines for the use of restraints, which would normally fall within the purview of child protection services, healthcare, or criminal justice systems. Given the sensitive nature of the subject, the appropriate handling, time limits, and authorization for restraints would typically be governed by specific local or country-specific laws and standards, that focus on child welfare and safety.