What it calculates
The main calculator finds elapsed time between a start and end time, subtracts an unpaid break, identifies overnight shifts, and shows both hours-and-minutes and decimal-hour results.
The clock-out planner works in reverse. It adds the paid hours and unpaid break to a starting time to estimate when the shift should end.
How overnight shifts work
When an end time is earlier than its start time, the calculator assumes the end occurs on the following day. For example, 10:00 PM to 6:30 AM is treated as an eight-hour, thirty-minute span.
Privacy by design
Calculator entries are processed to produce the requested result and are not stored in an application database. The selected light or dark theme may be saved in your browser so the site remembers your preference.
History
The original AoM Time System was created in 2023. It was rebuilt in 2026 with updated dependencies, mobile support, accessibility improvements, overnight-shift handling, and a clock-out planner.
Accuracy
The arithmetic is deterministic, but employers may apply their own time-clock rounding, break, overtime, or payroll rules. Use the result as a calculation aid and verify it against the policy that applies to you.