Other

Date Calculator

Find the difference between dates and add calendar or business days.

Inputs

Defaults are prefilled so the result is visible immediately.

Start date

End date

Days to add

Add as business days

Results

Results update as the calculator inputs change.

Date difference

239 days

Weeks

34.14

Signed difference

239 days

Date after add-days

Jun 5, 2026

ISO date

2026-06-05

Formula and Assumptions

Date difference counts whole elapsed calendar days; add-days mode optionally skips weekends.

Business-day addition skips Saturdays and Sundays.

The signed difference is negative when the end date is before the start date.

Reference Upgrade

Built from the Calculator.net model, with added context.

Live validation and instant result updates instead of a submit-only workflow.

Multiple decision metrics are shown together, not only the primary answer.

Formula notes and assumptions are visible on the page so the math is easier to audit.

Reference Model

Modeled after the input style and primary output on Calculator.net's Date Calculator.

The page keeps the math in one place and exposes the assumptions beside the result.

Default inputs: startDate=2026-05-06, endDate=2026-12-31, addDays=30, businessDays=false