'值班' (zhí bān) is a verb meaning 'to be on duty' — that is, to perform assigned work during a specific shift or period, especially when others are off-duty or unavailable. The character 值 (zhí) means 'to take charge of' or 'to guard', and 班 (bān) means 'shift', 'team', or 'class'; together, they literally convey 'taking charge of the shift'. This term is commonly used in workplaces, hospitals, schools, security services, and emergency response settings.

It implies responsibility for monitoring, maintaining operations, handling unexpected issues, or providing essential services during designated hours. Unlike general work (工作), 值班 specifically refers to scheduled, often rotating, duty periods — sometimes overnight or on holidays. It can be done by individuals or teams, and may involve standby readiness rather than active tasks throughout the entire time. The verb typically takes time expressions (e.g., 今天, 明天晚上) or duration markers (e.g., 24小时), and is often followed by location or purpose (e.g., 在办公室值班, 为病人值班).