HolidayDB calculators
These calculators are backed by HolidayDB public holiday data. Use them in the browser for quick checks, or use the API documentation links to integrate in your own software.
HolidayDB calculators help you work with business days, working hours, payroll periods, PTO accrual, SLA deadlines, delivery estimates, and long weekend planning — reliably across countries and regions.
All calculators use country-specific public holiday data and configurable work schedules, so results match real operational timelines (not naive calendar-day math).
| Calculator | What it does | API docs |
|---|---|---|
| Business days calculator | Count working days in a month or year with ISO weekdays and optional regional holidays. | Documentation |
| Working hours calculator | Compute working hours for a range, month, or year using holiday rules plus a workday duration. | Documentation |
| Salary proration calculator | Prorate salary by working days in a window inside a payroll period (excluding holidays). | Documentation |
| Leave / PTO calculator | Model leave accrual and leave taken using working days/hours and public holidays by country and region. | Documentation |
| SLA deadline calculator | Add business days to a start date, skipping weekends and public holidays by country/region. | Documentation |
| Delivery date calculator | Estimate delivery dates by adding business days (skipping weekends and public holidays). | Documentation |
| Bridge days calculator | Find bridge-day opportunities around weekends and public holidays to plan long weekends. | Documentation |
Business day, payroll, and PTO calculators
HolidayDB calculators are designed for workflows where calendar days are not enough.
Many business operations depend on:
- working days
- public holidays
- regional holiday calendars
- custom work schedules
- payroll periods
- SLA timing
- leave accrual rules
Using plain calendar calculations often leads to inaccurate payroll, delivery estimates, staffing plans, and operational deadlines.
HolidayDB calculators solve this by combining:
- country-specific public holiday data
- configurable working schedules
- regional holiday rules
- business-day-based logic
The calculators can be used directly in the browser or integrated into software using the HolidayDB APIs. For payroll and HR workflows, start with the salary proration calculator and the leave / PTO calculator. For scheduling, see business days and working hours. For planning time off, try bridge days.
Common use cases
- payroll and salary proration
- PTO and leave tracking
- SLA deadline calculations
- delivery and shipping estimates
- workforce planning
- contractor billing
- project planning
- operations scheduling
- long weekend and vacation planning
Why business-day calculations matter
Calendar days and working days are not the same.
A 5-day deadline may mean:
- 5 calendar days
- 5 business days
- 5 working shifts
- or 5 region-specific working days
Public holidays also vary by country, region, and subdivision — and workweeks differ between industries and geographies.
For example:
- public holidays vary significantly between countries
- Gulf countries may use Sunday-to-Thursday schedules
- regional holidays can affect payroll and delivery timelines
This is why business-day-aware calculations are important for payroll, HR, logistics, support operations, and international teams.
Built for both browser use and APIs
All calculators are backed by HolidayDB API endpoints, so the same business-day and public-holiday logic can be reused in payroll systems, HR software, logistics tools, SaaS platforms, and internal automation.
See the API documentation for endpoint details and examples.
Calculator categories
HolidayDB calculators are grouped into several categories:
Payroll and HR calculators
Time and scheduling calculators
Operations and delivery calculators
Vacation and planning calculators
Each calculator uses the same underlying holiday and working-day logic, ensuring consistent results across tools and APIs.
Country & year guides
Country and year guides provide pre-built calendar references using the same HolidayDB public holiday and business-day logic as the calculators above.
These guides are useful when you need quick reference data without configuring inputs manually, like:
- working days by country and year
- working hours estimates
- public holiday calendars
- bridge-day opportunities and long weekends
Working days
Business days per month/year by country (weekends + public holidays excluded).
Working hours
Working time estimates by country/year (built from business days + holiday rules).
Long weekends
Bridge-day opportunities ranked by efficiency for planning time off.
Public holidays
National public holiday lists by country and year.
Frequently asked questions
What is a business day?
A business day is a working day excluding weekends and public holidays.
Do calculators account for public holidays?
Yes. HolidayDB calculators automatically exclude public holidays based on the selected country and optional region (when supported by your plan).
Can I use custom work schedules?
Yes. Most calculators support schedules such as:
- Monday to Friday
- Monday to Saturday
- Sunday to Thursday
- every day
Are regional holidays supported?
Yes. Many calculators support subdivision or regional public holiday rules.
Can I use the calculators via API?
Yes. Every calculator is backed by a HolidayDB API endpoint documented in the API docs.
Which calculators are useful for payroll?
The salary proration calculator and leave / PTO calculator are designed specifically for payroll and HR workflows.