Time Duration Calculator
Compute duration between two times or add/subtract an interval — with cross-midnight support.
Explanation
This Time Duration Calculator helps you compute the difference between two times (duration) or add/subtract an interval from a base time. It’s useful for shift planning, timesheets, study sessions, travel timing, and productivity tracking.
Tip: For overnight shifts, enable Cross midnight so the end time is treated as the next day.
Formula
Duration (seconds) = end_seconds − start_seconds If Cross midnight and end < start: end_seconds += 24×3600
FAQs
Cross midnight?
If end time is earlier than start time, enable cross-midnight to treat the end as next day.
Format?
Outputs include HH:MM:SS, decimal hours, total minutes, and total seconds.
Timezones?
Convert both times to the same timezone before comparing if they come from different zones.
Business use?
Perfect for timesheets, shift durations, billing hours, and project tracking.
Precision?
Seconds precision is supported. Milliseconds are not shown to keep the UI simple.