# iCal Tester - Complete Documentation

> Free online tool for testing and validating iCal/ICS calendar feeds
> for vacation rental platforms and PMS integrations.

## Links

- Homepage: https://icaltester.com/
- Sign Up (Free): https://icaltester.com/auth
- Guides Hub: https://icaltester.com/guides
- Airbnb Guide: https://icaltester.com/guides/airbnb-ical-not-syncing
- Booking.com Guide: https://icaltester.com/guides/booking-com-calendar-sync-test
- RFC-Aware Validator Guide: https://icaltester.com/guides/ical-rfc-5545-validator
- Privacy Policy: https://icaltester.com/privacy
- Contact: https://icaltester.com/contact

## What is iCal Tester?

iCal Tester validates iCalendar feeds with an RFC-aware, behavior-first
workflow and helps developers test calendar synchronization with
Booking.com, Airbnb, VRBO, and other OTA platforms.

It is strongest when you need to know:
- whether a feed can be fetched
- whether events import cleanly
- whether blocked dates match the final booking outcome you expect

It is not a full RFC 5545 conformance checker.

## Key Features

- Validate iCal/ICS feeds through import and sync behavior
- Test calendar sync between vacation rental platforms
- Detect booking conflicts and double bookings
- Create mock calendars for integration testing
- Visual timeline view for comparing multiple calendars
- Debug channel manager and PMS integrations

## Current ICS Functionality

The shared ICS layer currently supports:
- folded-line handling
- VEVENT extraction
- UID, DTSTART, DTEND, SUMMARY, STATUS parsing
- calendar metadata extraction
- basic diagnostics
- DTEND auto-correction when end is missing or invalid
- floating datetimes treated as UTC

Current limitations:
- no full timezone conversion for `TZID`
- no RRULE expansion
- no full RFC 5545 compliance verdict
- diagnostics/reporting exist in backend code but are not fully exposed as a user-facing report flow

## Primary Use Cases

1. **Test Booking.com Calendar Sync**: Import your Booking.com iCal
   export and compare it against mock calendars to prevent double bookings.

2. **Debug Airbnb iCal Exports**: Troubleshoot why your Airbnb calendar
   isn't syncing and validate how the imported feed behaves.

3. **Channel Manager Testing**: Verify your PMS correctly reads and
   writes iCal data across multiple OTA channels.

4. **RFC-Aware Validation**: Check whether your calendar feeds can be
   imported, synced, and translated into the blocked dates you expect.

## How to Use iCal Tester

### Step 1: Create an Account

Sign up for free at https://icaltester.com/auth using your email.
No credit card required.

### Step 2: Create a Calendar

Click "Add Calendar" to create a new test calendar. Give it a descriptive
name like "Booking.com Test" or "Airbnb Integration". Each calendar gets
a public iCal feed URL you can use in other systems.

### Step 3: Add Bookings or Subscribe

You have two options:

**Manual Bookings**: Add test bookings directly with:
- check-in and check-out dates
- booking status

**Subscribe to External Feed**: Paste an external iCal URL from:
- Booking.com
- Airbnb
- VRBO
- Google Calendar

### Step 4: View Timeline

Open the Timeline view to see calendars side-by-side on a visual
calendar grid. Conflicts and overlaps are highlighted so you can
spot double bookings quickly.

### Step 5: Export Your Feed

Copy your calendar's public iCal URL to test in your PMS or channel
manager:

```text
https://icaltester.com/ics-feed/{your-calendar-token}
```

The generated feed is intended for broad iCal/ICS compatibility in
common import workflows.

## Testing Booking.com Calendar Sync

### Quick Start

1. Copy your Booking.com iCal export URL from your listing dashboard
2. Add it as a subscription in iCal Tester
3. Create mock calendars to simulate other channels
4. Check the Timeline view for conflicts and overlaps

### What You Can Test

- last-minute cancellations
- overlapping stays across channels
- modified reservations
- blocked-date behavior after import
- cross-channel booking mismatches

### Common Issues

**Feed not updating?** Check the "Last updated" time in Booking.com
and reload in iCal Tester. Booking.com may cache exports.

**Missing bookings?** The ICS file may be cached, malformed, or only
partially imported. Validate the sync result and compare imported
events with the timeline outcome.

## Debugging Airbnb iCal Exports

Airbnb iCal exports can silently fail or go out of sync, causing
double bookings across your channel manager.

### Key Points

- Airbnb caches calendar exports for approximately 2 hours
- Changes may not appear immediately in your PMS
- Common issues: malformed VEVENT blocks, floating datetimes treated
  as UTC, stale exports, or blocked requests

### Quick Start

1. Go to Airbnb > Your Listing > Availability > Export Calendar
2. Copy the iCal URL and paste it into iCal Tester
3. Check import behavior and view events on the timeline
4. Add mock calendars to test for booking conflicts

### Why Is My Airbnb iCal Not Syncing?

Common causes:
- Airbnb's cache delay
- malformed VEVENT blocks in the export
- floating datetimes or date-window mismatches
- blocked or rate-limited requests returning stale data

Use iCal Tester to validate the raw feed and identify import and
blocked-date issues.

## Public SEO Guides

### Airbnb iCal Not Syncing? How to Debug It

URL: https://icaltester.com/guides/airbnb-ical-not-syncing

Workflow:
1. Copy the Airbnb export URL
2. Add it as a subscription in iCal Tester
3. Force the first sync
4. Compare imported bookings on the timeline

### How to Test Booking.com Calendar Sync

URL: https://icaltester.com/guides/booking-com-calendar-sync-test

Workflow:
1. Get the Booking.com export feed
2. Subscribe to it in iCal Tester
3. Run a sync immediately
4. Check for cross-channel conflicts

### RFC-Aware iCal Validator Workflow

URL: https://icaltester.com/guides/ical-rfc-5545-validator

Workflow:
1. Import the feed as a subscription
2. Force a sync and inspect logs
3. Check imported event behavior
4. Validate the final booking outcome on the timeline

## Frequently Asked Questions

### What is an ICS file?

An ICS file is a calendar data file following the iCalendar format
(RFC 5545). It contains events with dates, times, descriptions,
and status information.

### What is RFC 5545?

RFC 5545 is the Internet standard for iCalendar data exchange.
It defines how calendar events should be formatted for interoperability
between systems.

### What causes iCal feed validation errors in this product?

Common issues the current parser can flag or surface include:
- missing VCALENDAR wrapper
- missing VERSION
- missing UID or DTSTART in VEVENT
- floating datetime without timezone
- DTEND before DTSTART
- invalid STATUS value
- RRULE present but not expanded

### What does the current parser not fully support?

The parser does not fully resolve `TZID` timezones and does not expand
recurring events from `RRULE`.

## Contact

- Website: https://icaltester.com
- Contact: https://icaltester.com/contact
- Developer: Globecom (https://globecom.nl)