Calculate Business Days Instantly & Accurately
Free calculator and powerful API for business day calculations, holiday calendars, and working hours. Built for developers who need precision.
No credit card required 500 free requests/month
Trusted for real-world deadlines
Used for SLAs, payroll cutoffs, delivery promises, and anything where “business day” must be precise.
“We stopped shipping dates that accidentally landed on public holidays. Our SLA tooling finally matches reality.”
Maya R.
Support Ops Lead
“The working hours math is the missing piece. It made payroll cutoffs and approvals dramatically simpler.”
Jonas K.
Backend Engineer
“Fast responses, predictable output, and a clean API. It feels like it was built by someone who actually uses it.”
Elena S.
Product Engineer
Everything You Need for Date Calculations
From simple business day counts to complex working hours arithmetic, we've got you covered.
9+ Countries
Accurate holiday calendars for US, UK, Germany, France, Netherlands, Canada, Australia, Japan, and India.
Lightning Fast
Edge-deployed API with sub-50ms response times globally via Cloudflare Workers.
Custom Calendars
Create custom calendars with your own holidays and working hours for any industry.
Developer Friendly
RESTful API with comprehensive documentation, code examples, and SDKs.
Working Hours
Calculate working hours between dates, perfect for SLA tracking and payroll.
ICS Export
Export calendars to ICS format for integration with any calendar app.
Calculate Business Days Now
See how easy it is to calculate business days with our free tool.
Mini demo
Weekends excluded. Holidays come in the full calculator + API.
From prototype to production
Start with the calculator, then move to the API when you need reliability, speed, and country-aware holiday logic.
Typical response
< 50ms
Countries
9+
Simple, Transparent Pricing
Start free, scale as you grow. No hidden fees.
Free
Perfect for testing and small projects
- 500 requests/month
- 9 country calendars
- Basic calculator
- Community support
Starter
For growing applications
- 10,000 requests/month
- All country calendars
- Custom calendars
- Email support
- No attribution
Pro
For production workloads
- 100,000 requests/month
- Working hours API
- Webhooks
- Priority support
- Usage analytics
Enterprise
For large-scale applications
- Unlimited requests
- SLA guarantee
- Dedicated support
- Custom integrations
- On-premise option
Frequently Asked Questions
Ready to Get Started?
Join thousands of developers using BusinessDays.io for accurate date calculations.