---
title: ToolRouter — Agent Use Case Guide
description: Step-by-step guide for completing a task with a specific AI agent using ToolRouter.
url: https://toolrouter.com/tools/public-holidays/use-cases/build-holiday-aware-calendars/copilot
---
# How to Build Holiday-Aware Calendars with Copilot

Copilot generates holiday-aware calendar data and the code to use it. Fetch holidays for target countries, create working-day lookup modules, and build business day calculators for your SLA, billing, or scheduling systems -- producing both data and application logic from your development environment.

## Setup

{"mcpServers":{"toolrouter":{"command":"npx","args":["-y","toolrouter-mcp"]}}}

## Steps

1. Add ToolRouter to Copilot MCP config
2. In Copilot Chat: "Get US public holidays for 2026"
3. Copilot returns the holiday data
4. Ask: "Generate a TypeScript module that exports working days per month for 2026"
5. Integrate the generated code into your application

## Example Prompt

```
Fetch US holidays for 2026 and create a JSON config file mapping each month to its working day count. I need this for our SLA calculator.
```

## Tips

- Generate working-day lookup functions for your application directly from the data
- Create holiday-aware date utilities for your codebase
- Automate annual calendar data updates as part of your build process
