About DeadlineDays

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.

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.

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.

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.

DeadlineDays is an independent site built and maintained by one developer, working from South Korea. The developer is not a lawyer, employment specialist, accountant, or tax adviser. Because of that, the site publishes its calculation rules, holiday data sources, per-country verification dates, and known limits. Corrections: [email protected]

Calculation or holiday-coverage corrections are reviewed against a reproducible input and, when relevant, a current official source. Material content changes receive a new review date only after the affected page has been checked. The public operations email is available for concise reports that include the page, country, date range, selected rules, observed result, and supporting source.

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.

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.

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.

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