What if the start is outside the work window?

It rolls forward to the next working day's start. Adding 1 h to Saturday at 03:00 with a Mon–Fri 9–17 window lands at Monday 10:00.

Does it handle partial hours?

Yes — the hours field accepts decimals (e.g. 2.5). Day-end overflow rolls cleanly to the next working day with the remaining fraction.

Add Business Hours to a Date

Time

Answers "if I start now and burn N working hours, when am I done?" — useful for SLA targets, ticket due dates, or planning effort that has to fit between 09:00 and 17:00 with weekends and holidays subtracted. Configurable work window, working-day toggles (Mon–Fri default, change for Sun-start cultures or 6-day weeks), and a free-form holiday list. The breakdown lists each working day touched and how many hours were consumed there.

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Start datetimeWorking hours to addWork start (hour, 0–23)Work end (hour, 1–24)

Working days

Holidays (YYYY-MM-DD per line)

End datetime

2026-06-11 17:00

Per-day breakdown · Total: 16 h / 2 d

Day	Hours used
2026-06-10	8.00 h
2026-06-11	8.00 h

Holidays are an explicit list — country calendars vary, so paste yours. Sub-day starts that fall mid-window are honored exactly.

How to use

Set the start datetime (defaults to now) and the work hours to add.
Configure your work window (default 9–17), toggle weekends, and paste any holidays as `YYYY-MM-DD` per line.
Result is the landing timestamp; the breakdown below shows the per-day split.

Frequently asked questions

What if the start is outside the work window?: It rolls forward to the next working day's start. Adding 1 h to Saturday at 03:00 with a Mon–Fri 9–17 window lands at Monday 10:00.
Does it handle partial hours?: Yes — the hours field accepts decimals (e.g. 2.5). Day-end overflow rolls cleanly to the next working day with the remaining fraction.