Date & working-days calculator

What it does

Count days between dates or add and subtract days, with optional weekend exclusion.

How to use it

1. Choose days between dates or add/subtract days. Use negative numbers to go backwards.
2. Between dates includes the start and excludes the end unless you select Include the end date. A same-date inclusive calculation counts one calendar day.
3. Working days exclude Saturdays and Sundays only, not public holidays. When adding, the start date is day zero.

Example

From Monday 14 September to Monday 21 September 2026 there are five working days, excluding the end date.

Methodology

Date-only arithmetic uses UTC day boundaries so daylight-saving changes do not alter calendar-day counts. Whole weeks contribute five working days.

Limitations

Years 0001–9999. Add or subtract at most 100,000 days. No public holiday calendars or local business schedules.

Automation

This tool runs in your browser. No upload API or MCP endpoint is available.