How this calculator works
This calculator computes duration between two clock times or adds minutes to a start time. Enter two clock times to see the duration, or enter a start time and minutes to add. Use it for scheduling, shift planning, and time arithmetic. The key inputs are two clock times or a start time and minutes to add. The output is the duration in hours and minutes, or the end time. Real-world applications include work scheduling, event planning, time management, and shift tracking. The calculator converts clock times to minutes, normalizes overnight spans, and converts the result back to clock format. If the end time is earlier than the start time, it treats the end time as the next day. It works with clock times only and does not convert time zones. This is useful for calculating how long tasks take or what time it will be after a certain duration.