When must a manager be on duty?

A manager must be on duty at all times when alcohol is available for sale or supply because this is crucial for maintaining compliance with licensing laws and ensuring responsible service of alcohol. The presence of a manager helps to reduce risks associated with alcohol service, such as over-serving patrons and addressing any issues that may arise in a licensed establishment. This requirement ensures that there is a trained and responsible individual available to oversee operations, make informed decisions, and handle situations that could affect the safety and well-being of both staff and patrons.

In contrast, the other options suggest limited scenarios during which management presence may not be required. For instance, only being on duty during peak hours or special events could leave gaps in oversight during quieter times when incidents could still occur and need management intervention. Similarly, only needing to be present during initial opening hours does not cover the entire operational period, which is particularly important in hospitality settings where alcohol is served.