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Private browser productivity tool

Due Date & Business Day Calculator

Add or subtract calendar or business days, exclude weekends and supplied holidays, and show the resulting weekday.

Free to use Your entries and results stay in this browser. Lucaden does not upload them.

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How it works

Complete the job in three clear steps

  1. Enter or choose a start date, day count, direction, and optional holidays.
  2. Use the available controls to create a calculated due date with an audit summary.
  3. Review, copy, or download the result before relying on it.

Important

Check the result before relying on it

Review generated output before using it in production. Formatters and converters can validate structure, but they cannot understand every application-specific rule or guarantee that transformed content has the intended meaning.

Practical details

What this Lucaden tool does

Add or subtract calendar or business days, exclude weekends and supplied holidays, and show the resulting weekday.

This is an independent Lucaden implementation using browser platform APIs. Entries are not submitted to Lucaden.

Included capabilities

  • Calendar or business days
  • Forward and backward calculation
  • Weekend exclusion
  • Custom ISO-date holidays

Useful for

  • Estimate invoice due dates
  • Plan review windows
  • Calculate filing preparation dates
  • Schedule project handoffs

Questions

About this tool

Does this know public holidays automatically?

No. Holiday calendars vary by place and year. Enter each applicable non-working date explicitly and verify legal or contractual deadlines with the governing rules.

Is the start date counted?

No. A one-day calculation moves to the next eligible day in the selected direction.

Keep going

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Open-source foundations

Built transparently

Lucaden documents its standards sources, architectural references, and permissive runtime dependencies while keeping this workspace consistent with the Lucaden interface.

Privacy-First ToolboxMIT architecture reference sourceIT-ToolsGPL-3.0 interface reference; no code copied sourceThird-party noticesLicenses and attribution