About DeadlineDays

DeadlineDays provides free browser-side business date calculators for deadline planning.

Purpose

DeadlineDays helps people make practical date decisions before they send an invoice, promise a shipping window, set an SLA target, prepare payroll, or compare working days in a month.

Calculator approach

Each calculator keeps the main assumptions visible: selected country, non-working days, public holiday handling, custom company holidays, and whether start or end dates are included.

Data and verification

Holiday-aware tools identify the public holiday data source near the calculator. Critical dates should still be checked against the governing contract, policy, official calendar, or service provider schedule.

Privacy-first access

The site is statically exported and designed to work without accounts, databases, or server-stored calculator inputs. Share links use URL parameters for calculator settings instead of a private workspace.

Free business date tools

The calculators are built for practical planning tasks such as counting workdays, adding business days, estimating invoice due dates, checking SLA deadlines, planning shipping dates, and reviewing payroll cutoffs.

Country and non-working day settings

Many calculators can combine country-based public holidays with the non-working days selected by the user, so a company that does not follow a standard Saturday/Sunday weekend can still model its own schedule.

Privacy-friendly by design

DeadlineDays does not require login and does not use a server database for calculator inputs. Calculations are intended to run in the browser, with shareable settings kept in the URL when needed.

Reference, not an official source

Results are general planning references. They are not legal, tax, payroll, accounting, employment, contract, SLA, or shipping carrier guarantees.