Adding or subtracting time durations, like figuring out what time it will be after adding several hours and minutes, or calculating the total duration of multiple time segments, involves carrying over hours and minutes correctly, which can be error-prone by hand. This time duration calculator lets you add or subtract hours, minutes, and seconds, correctly handling the carry-over between units (60 seconds = 1 minute, 60 minutes = 1 hour). It's useful for calculating total time spent on tasks, figuring out arrival times after a journey of known duration, or summing up multiple time intervals for billing or scheduling purposes. Enter your time values and operation to get an instant, accurate result.