# How can I check the content of an iCal calendar?

You can use this tool which is very handy to reproduce a server-to-server call to your HBook iCal calendar URL: [https://icalendar.org/validator.html](https://icalendar.org/validator.html)

1. Enter the URL of your HBook iCal calendar. You will find it in **HBook > iCal sync**, when clicking on “Get export URL” for one of your accommodation.
2. Click on “Validate”. When validating, you will be shown with a message informing you if the calendar is correctly formatted or if there are any errors.
3. Click on “Show source”. This will display the content returned. If the validation step returned an error indicating that it is not an iCal file/calendar, you can view here the content that has been returned by the server.