Helene Groenberg

WhenPilot is a lightweight appointment booking plugin for small businesses — salons, clinics, consultants, tutors. Everything stays on your own site; there is no third-party booking service.
Features
<ul>
<li>Define services (name, duration, optional price, description).</li>
<li>Set your weekly opening hours in a simple text format (e.g. <code>Mo-Fr 09:00-17:00</code>).</li>
<li>Visitors book with the <code>[whenpilot]</code> shortcode: pick a service, a date, and a free time slot computed from your hours and existing bookings.</li>
<li>Double-booking prevention: slots are re-validated on the server before saving, with a configurable capacity (e.g. number of staff).</li>
<li>Admin inbox: see upcoming/pending/confirmed/cancelled bookings, confirm, cancel or delete.</li>
<li>Email confirmations to the customer and a notification to you, plus emails when you confirm or cancel.</li>
<li>Configurable lead time, how far ahead people can book, currency label and an optional auto-confirm.</li>
<li>Uses your site’s timezone. Works with any theme.</li>
</ul>
Usage: create a page, add the shortcode <code>[whenpilot]</code>, and publish.
All features described above are fully functional in this plugin — no time limits, no usage caps, no locked options. WhenPilot does not connect to any external service. A separately distributed companion plugin offers additional features (multiple staff/resources with custom fields, automatic email reminders) but is not required for the plugin to work.
<h3>Privacy</h3>
Bookings (name, email, optional phone and notes) are stored in your own database and emailed to you and the customer. No data is sent to any third party.

WhenPilot

Self-hosted appointment booking: services, weekly hours, free-slot picking, double-booking prevention and email confirmations.

supersaas

SuperSaaS is a flexible online appointment scheduling system that works with many different businesses and is available in over 28 languages. The basic version is free, a paid version is available for large users and commercial use.
The plugin can automatically log a user into a SuperSaaS schedule using his WordPress username. It passes along the user’s information, creating or updating the user’s information on SuperSaaS as needed. This saves users from having to log in twice.
<h4>MORE INFORMATION</h4>
Read the <a href="https://www.supersaas.com/info/doc/integration/wordpress_integration" rel="nofollow ugc">SuperSaaS WordPress Plugin documentation page</a> for information about how to install and setup the plugin in WordPress. Visit the <a href="https://www.supersaas.com" rel="nofollow ugc">supersaas.com</a> website for an overview of all features of the booking system.
<h3>Languages</h3>
SuperSaaS is available in over 28 languages. Check out the <a href="https://www.supersaas.com" rel="nofollow ugc">SuperSaaS</a> website for more information.

SuperSaaS – online appointment scheduling

Does not work

SuperSaaS is a flexible appointment scheduling system that works with many different businesses. The basic version is free.

WhenPilot vs SuperSaaS – online appointment scheduling