# Phase 3A -- Schedule URL Serializer/Parser

> **Parent:** `2026-04-15-phase-3-schedule-master.md`
> **Depends on:** Phase 2B (reuses parseFlightUrlParams, buildFlightUrlParams)

## Goal

TDD implementation of URL parser/builder for the schedule feature covering:
1. Start page
2. One-way route search
3. Round-trip route search
4. Multi-flight details (catch-all)

## Deliverables

1. `src/features/schedule/types.ts` -- schedule-specific types
2. `src/features/schedule/url.ts` -- parse/build functions
3. `src/features/schedule/url.test.ts` -- comprehensive tests

## URL Format Reference

### Route params: `{dep}-{arr}-{dateFrom}-{dateTo}[-{timeFromTo}][-C{connections}]`
### Details: `{flight1-date}[/{flight2-date}]...` or with airport codes interleaved

## Tasks

T1. Create schedule types
T2. Write URL test file (TDD -- tests first)
T3. Implement url.ts to pass all tests
