RuleDate Deadline Calculator

How it works

Chain date operations (add business days, add months with clamping, end of month, roll to next business day) on a start date. RuleDate uses public holidays for 16 countries and their subdivisions (2024–2030) and shows every skipped date with its reason, so the result can be checked rather than trusted.

• A business day is a day that is not a selected weekend day, not a public holiday of the chosen country (nationwide, or of the chosen subdivision) and not an extra closure date. Only Nager.Date entries of type "Public" count; bank, school, optional and observance days are ignored.
• Add business days counts business days after the start date (the start date itself is not counted); negative amounts count backwards. Every non-business day passed over is listed with all its reasons.
• Add calendar days / weeks ignore holidays. Add months keeps the day of month; if it does not exist, "clamp" uses the month’s last day and "overflow" rolls into the next month.
• End of month moves to the last calendar day of the month that is `amount` months after the current date. Next / previous business day roll only if the current date is not a business day (following / preceding convention).
• Optional final rule modelled on § 193 BGB: if the result falls on a Saturday, Sunday or a public holiday at the chosen place, it moves to the next day that is none of these (extra closures and custom weekends are ignored for this rule).
• Holiday data covers 2024–2030; dates outside that range are checked for weekends and closures only and trigger a warning.

Not legal advice. Statutory and contractual deadlines have their own rules (start-day exclusion, service dates, court holidays, local holidays); verify critical deadlines with a qualified professional.

Sources

• § 193 BGB – Sonn- und Feiertag; Sonnabend (Bundesministerium der Justiz / gesetze-im-internet.de)