Hours Calculator

Round to: Mode:

Drag & drop CSV/TXT with rows like: 2025-10-29, 21:00, 05:30, 30 (date, start, end, break-min). Nothing is uploaded.

Tip: Overnight is fine (e.g., start 22:00 → end 06:30). Break is minutes to subtract (optional).

Date	Start	End	Break (min)	Duration (h)	Actions

Duration updates automatically as you type.

Examples (auto-fill rows):

Hours Calculator – Quick Cheat Sheet

Inputs: date, start time, end time, and optional break minutes (subtracted).
Overnight: allowed (e.g., 22:00 → 06:30 next day).
Modes:
- Auto: uses your local timezone and calendar; DST transitions are reflected (e.g., 25h or 23h days).
- Naive: strict wall-clock math (end − start ± 24h if end < start), ignores DST shifts.
Rounding: optional to the nearest 1, 5, 6 (tenth-hour), 10, 15, or 30 minutes (applied per-row and to totals).
CSV/TXT import: local-only; format: YYYY-MM-DD, HH:MM, HH:MM, break_min. Extra spaces allowed.
Validation: times must be HH:MM (24-hour). Break cannot exceed the raw span.

Edge cases & notes

Empty rows are ignored in totals.
Rounding uses “nearest” behavior (0.5 rounds up). Totals recompute from rounded rows.
To lock a day with no break, set break to 0.