Chronological units are standard measurements used to organize and describe time. They help us understand the sequence of events in history or daily life. Common units include seconds, minutes, hours, days, months, and years. Each unit represents a specific duration, allowing us to break down time into manageable parts. These units are essential for scheduling, planning, and recording events. For example, a year can be divided into months, which can further be divided into weeks and days. This structured approach helps us track progress, celebrate anniversaries, and understand historical timelines.