Date Duration & Business Days Calculator

Count days, weeks, and business days between dates. Add or subtract working days with US/UK holidays and share deep links like /time/duration?start=2025-11-01&end=2025-12-15&bizdays=US.

Use negative numbers to count backwards.

Calendar span

7 days

Inclusive: 8 days

Dec 15, 2025Dec 22, 2025

Weeks & weekdays

1w 0d

6 weekdays · 2 weekend days

Business days (US)

6

Includes weekends + region-specific holidays

Add/Subtract business days

Starting from Dec 15, 2025, moving forward 5 working days in the US calendar lands on:

Monday, December 22, 2025

Business days skip weekends plus official holidays for the region you selected.

Deep-link any scenario by sharing URLs like /time/duration?start=2025-11-01&end=2025-12-15&bizdays=US.

Upcoming holidays (US)

Keep these non-working days in mind when planning timelines.

Christmas Day

Thursday, December 25, 2025

New Year's Day

Thursday, January 1, 2026

Martin Luther King Jr. Day

Monday, January 19, 2026

Presidents' Day

Monday, February 16, 2026

Memorial Day

Monday, May 25, 2026

Juneteenth

Friday, June 19, 2026

Why planners link here

Legal, finance, and operations teams need a single source of truth for date math. Tinapps tracks weekdays, weekends, and observed holidays so remote teams agree on timelines without emailing screenshots.

Workflow ideas

  • Attach a deep link to SOWs so clients can see exactly how many working days span a milestone.
  • Embed the business-day offset in incident runbooks to forecast postmortem due dates.
  • Share upcoming holiday lists during handoffs so teams see when coverage gaps might occur.