Working days calculator API. Business days in one call.
Pass a start and end date, plus an optional country and subdivision — get back the number of working days, excluding weekends and public holidays.
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What the Working Days Calculator API Does
One endpoint. The number of business days between two dates, with optional country and subdivision holiday adjustments.
Structured output
Every response includes the working-day count, the requested date range echoed back, and the country/subdivision used for holiday exclusion — ready to plug into scheduling or billing logic.
{
"working_days": 4,
"from": "2024-02-23",
"to": "2024-02-28",
"country": "US",
"subdivision": "NY"
}
Simple to integrate
Two required parameters: from and to. Add country and subdivision for holiday-aware calculations. A single GET request returns everything a scheduling tool needs.
GET /v1/places/working-days?from=2024-02-23&to=2024-02-28&country=US
Host: requiems.xyz
requiems-api-key: YOUR_API_KEY
Calculate Business Days in Any Workflow
From project planning to payroll systems — any product that deals with deadlines can use the Working Days Calculator API.
Estimate realistic project deadlines
Calculate business-day turnaround times for tasks and milestones, automatically excluding weekends and holidays.
Estimate delivery windows
Show customers accurate delivery date ranges by counting only working days in the country they're shipping to.
Calculate payroll and billing cycles
Determine the number of billable working days in a pay period, adjusted for the employee's country and region.
Track SLA response deadlines
Calculate business-day SLA deadlines for support tickets, excluding weekends and public holidays in the customer's country.
Plan vacation and leave requests
Show employees how many working days a requested leave period actually covers, accounting for public holidays.
Add business-day logic to your platform
Integrate working-day calculations into scheduling, CRM, or project management tools via a single authenticated API call.
Use together with complementary APIs.
Working Days Calculator works even better when paired with other Requiems APIs.
Benefit: Look up the specific public holidays behind a working-day calculation.
Outcome: Show users exactly which dates were excluded and why, alongside the working-day count.
Benefit: Combine business-day counts with local time zone context for global teams.
Outcome: Schedule cross-timezone deadlines that respect both local holidays and local business hours.
Benefit: Pair loan processing timelines with business-day-aware deadline calculations.
Outcome: Give borrowers realistic closing-date estimates that account for weekends and holidays.
Frequently Asked Questions
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Add working-day calculations to your product with Requiems.
One API key. Working days, holidays, timezone, and 50+ other APIs.