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DateToolsHQ

Date & business time utilities

Date & Business Time Calculators

Calculate business days, deadlines, notice periods, invoice due dates, countdowns, and date differences.

42 calculators · 19 guides

Calculation rules and assumptions are documented on each calculator page.

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Built for everyday date calculations

  • Business days and working days
  • Invoice and contract deadlines
  • Notice periods and SLA targets
  • Countdowns and date differences

Browse by Category

Business Time tools are listed first for invoice, contract, and deadline planning.

Business Time Tools

Calculate business days, deadlines, due dates, notice periods, and SLA targets.

Browse business time guides

Countdown calculators

Count down to a custom date or major holidays—calendar days, optional UTC times, and seasonal pages for Good Friday, Easter, Labor Day, Memorial Day, Father's Day, Mother's Day, Independence Day, Valentine's Day, Halloween, Thanksgiving, Black Friday, Cyber Monday, Christmas, and New Year.

Date calculators

Count calendar days, age, and precise differences between dates.

Guides

Plain-language references for business days, net terms, deadlines, and calculator selection.

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Resources

How DateToolsHQ works

Pick a calculator from the categories below or use search in the header. Each page explains what it counts, which inputs it needs, and how to read the output.

Most tools update results as you type. Country and year pages show pre-calculated summaries for common planning questions.

Why use DateToolsHQ

Spreadsheets and mental math work, but a focused calculator saves time when you only need one answer—days until a deadline, prorated rent for a partial month, or hours over a weekly threshold.

Pages are written in plain language with related tools linked on each calculator. Long-form guides on this page cover business days, net terms, deadlines, and when to use each tool.

Learn more: Browse all guides

Accuracy and limitations

Holiday calendars and payroll outputs are simplified models. They do not replace HR systems, legal advice, or official government publications.

Read the disclaimer on each calculator page for category-specific notes.

Learn more: About · Contact · Disclaimer

Frequently asked questions

Is DateToolsHQ free?
Yes. All calculators on DateToolsHQ are free to use. We do not require an account or payment to run a calculation.
Are the calculators accurate?
Each tool follows documented rules on its page, such as UTC calendar math or optional holiday lists. Results are estimates for planning. Double-check important dates and amounts with your own records or official sources.
Do the tools account for holidays?
Business and working day calculators can exclude weekends and, where noted, sample holiday lists. Country and year pages show simplified national holiday calendars. Employer, regional, and contract rules may differ.
Can I use these results for payroll or legal decisions?
No. DateToolsHQ provides informational estimates only. Payroll, tax, employment, lease, and legal outcomes depend on laws, contracts, and employer policies. Consult qualified professionals before acting on any result.