CMS-Buttler

CMSB Kalender is a lightweight availability calendar for WordPress. It reads events from one Google Calendar iCal URL and displays the current month as available or booked.
Included in this WordPress.org version:
<ul>
<li>Shortcode <code>[cmsbkalender]</code></li>
<li>One Google iCal calendar</li>
<li>Current month display</li>
<li>Free/booked color display</li>
<li>Mobile layout</li>
<li>Optional legend</li>
<li>Custom labels for available and booked days</li>
<li>Server-side iCal loading with configurable cache time</li>
</ul>
Larger CMS-Buttler calendar versions with extended functionality are available as separate products outside this WordPress.org plugin package: https://cms-buttler.de/cmsb-kalender/
<h3>More powerful CMS-Buttler calendar versions</h3>
The WordPress.org version is intentionally focused on a clear and lightweight free/booked month view. It is suitable when you only need to publish basic availability from one Google Calendar.
The larger CMS-Buttler calendar products are separate packages outside this WordPress.org plugin and are designed for halls, clubs, venues, municipalities, rental locations, sports facilities, and organizations that need more control over public availability.
Compared with many simple calendar plugins, the larger CMS-Buttler calendar versions focus on privacy-conscious occupancy display instead of publishing every event detail. They can show that a day is booked while hiding names, internal notes, rental details, or private information.
Additional capabilities available in the larger CMS-Buttler calendar products may include:
<ul>
<li>Multiple months instead of only the current month</li>
<li>Half-day and partial-day occupancy with diagonal day display</li>
<li>Configurable split hour for morning and afternoon bookings</li>
<li>Mouseover details for events that are allowed to be public</li>
<li>Privacy rules for private, confidential, and default-visibility Google Calendar events</li>
<li>Keyword-based hiding for event titles and descriptions</li>
<li>Description trimming from an internal marker such as <code>Intern:</code></li>
<li>Optional booked label when hidden event details are suppressed</li>
<li>Extended design controls for colors, borders, legend, navigation, and day shape</li>
<li>Manual synchronization for testing calendar changes immediately</li>
<li>Sync status with information about loaded, skipped, changed, and recurring events</li>
<li>Recurring Google Calendar event handling</li>
<li>Website-side calendar cache clearing without changing the Google Calendar itself</li>
<li>Larger package options for agencies or operators managing more complex calendar setups</li>
</ul>
These larger versions are especially useful when the public website should answer the visitor’s main question quickly: “Is this date available or already booked?” At the same time, internal information can remain inside Google Calendar.
More information is available at https://cms-buttler.de/cmsb-kalender/
<h3>External Services</h3>
This plugin can use Google Calendar / Google iCal when a calendar URL is configured by the site administrator.
Google Calendar / Google iCal: 
The plugin requests the iCal URL entered by the site administrator in order to load calendar events. The request is made server-side from the WordPress installation to the configured iCal URL. Data processed by Google depends on the calendar configuration and Google’s policies. 
Service provider: Google LLC 
Terms: https://policies.google.com/terms 
Privacy: https://policies.google.com/privacy

CMSB Kalender

Display Google Calendar availability as a simple free/busy calendar with a WordPress shortcode.

Killian Santos

Icalviz connects to any public iCal feed and displays your availability day by day on any page or post, using a simple shortcode. Works with Google Calendar, Outlook, Apple Calendar, Nextcloud, and any service that exposes a public <code>.ics</code> link.
Each day is automatically classified:
<ul>
<li>🟢 Free — no events scheduled</li>
<li>🟡 Partial availability — some time slots are taken</li>
<li>🔴 Fully booked — your entire working hours are covered</li>
</ul>
Visitors can click any day to see occupied time slots in a clean timeline modal. Optionally display a call-to-action button (e.g. “Book this slot”) that links to your booking system.
Why Icalviz?
Stop copy-pasting your schedule into a webpage. Connect your Google Calendar, Outlook, Apple Calendar, or any iCal-compatible calendar — Icalviz reads your public iCal feed and updates automatically, every 30 minutes.
<h4>Use cases</h4>
🏢 Meeting room & shared space booking — Display a room’s availability calendar so your team or clients can instantly see open slots, without logging into any system.
📅 Show your public availability as a freelancer or consultant — Let potential clients see when you are free before they even reach out. Display months of availability from your Google Calendar, Outlook or any iCal feed in seconds.
🎓 Training sessions & open office hours — Show students or participants which session slots are still open. Mark them as full automatically when your agenda is blocked.
🏡 Seasonal rental & short-stay property — Display your gîte, studio, or vacation rental availability directly on your WordPress site, synced live from any iCal-compatible calendar.
🚗 Fleet & equipment availability — Track and display the availability of a shared vehicle, camera kit, or any bookable asset — simply by blocking time in Google Calendar, Outlook, or any other iCal calendar.
<h4>Key features</h4>
<ul>
<li>Zero configuration — Paste your iCal URL, copy the shortcode, done.</li>
<li>No API key required — Works with any public iCal feed: Google Calendar, Outlook, Apple Calendar, Nextcloud, and more.</li>
<li>Responsive — 2 columns on desktop, 1 on mobile. Navigation arrows for multi-month views.</li>
<li>Timeline modal — Click a day to see occupied time slots in a visual hourly timeline.</li>
<li>Call-to-action button — Add a custom button (e.g. “Request a slot”) inside the modal, linking to your booking page or contact form.</li>
<li>Custom labels — Rename “Free”, “Partial availability”, “Fully booked” to match your vocabulary.</li>
<li>Dark mode — Built-in light and dark themes.</li>
<li>Booking window — Limit how many days ahead users can see (e.g. next 90 days only).</li>
<li>Onboarding wizard — Step-by-step setup guides you from iCal URL to ready shortcode in under a minute.</li>
<li>Inline iCal tester — Paste a URL and instantly see whether it connects, how many events it contains, and what the next upcoming events are.</li>
<li>Debug panel — One-click diagnostic report covering WordPress environment, plugin version, cache status, iCal feed health, and slot calculation trace. Designed for quick support.</li>
</ul>
<h4>How it works</h4>
<ol>
<li>Get your public iCal URL (<code>.ics</code> link) from your calendar app:
<ul>
<li>Google Calendar: ⋮ → Settings and sharing → Make available to public → Public address in iCal format</li>
<li>Outlook: Calendar settings → Shared calendars → Publish → ICS link</li>
<li>Apple Calendar / iCloud: Calendar settings → Public Calendar → Copy link</li>
<li>Any other app: look for “Subscribe”, “iCal export” or “public ICS link”</li>
</ul>
</li>
<li>In WordPress: go to Settings → Icalviz, paste your iCal URL and follow the 3-step wizard.</li>
<li>Copy the generated shortcode and paste it into any page or post.</li>
</ol>
<h4>Shortcode reference</h4>
Basic: 
 [icalviz url=”https://calendar.google.com/calendar/ical/…/basic.ics”]
All options: 
 [icalviz url=”…” start=”9″ end=”17″ months=”3″ days_ahead=”90″ show_titles=”0″ disable_modal=”0″ legend=”1″ theme=”light” lbl_free=”Available” lbl_partial=”Limited availability” lbl_full=”Fully booked” cta_label=”Request this slot” cta_url=”https://your-booking-page.com”]
<ul>
<li><code>url</code> (required) — Your public <code>.ics</code> iCal link (Google Calendar, Outlook, Apple Calendar, etc.)</li>
<li><code>start</code> (0–23, default: 8) — Start of your working day in hours</li>
<li><code>end</code> (1–24, default: 18) — End of your working day in hours</li>
<li><code>months</code> (1–12, default: 2) — Number of months to display</li>
<li><code>days_ahead</code> (0–730, default: 0) — Days ahead to show; 0 = unlimited</li>
<li><code>show_titles</code> (0 or 1, default: 0) — Show event titles in the modal timeline</li>
<li><code>legend</code> (0 or 1, default: 1) — Show colour legend below calendar</li>
<li><code>theme</code> (light / dark, default: light) — Colour theme</li>
<li><code>lbl_free</code> (text, default: Free) — Label for free days</li>
<li><code>lbl_partial</code> (text, default: Available) — Label for partially available days</li>
<li><code>lbl_full</code> (text, default: Fully booked) — Label for fully booked days</li>
<li><code>cta_label</code> (text) — Text for the call-to-action button in the modal</li>
<li><code>cta_url</code> (URL) — Link for the call-to-action button</li>
<li><code>disable_modal</code> (0 or 1, default: 0) — Disable day-click modal; show only availability colour</li>
</ul>
<h4>Privacy</h4>
Icalviz connects only to the iCal URL you provide. No data is sent to any third party. The iCal feed is cached locally in your WordPress database for 30 minutes. If <code>show_titles</code> is set to 0 (default), event titles are never exposed to visitors.
<h4>Requirements</h4>
<ul>
<li>WordPress 5.8 or higher</li>
<li>PHP 7.4 or higher</li>
<li>A public iCal URL (<code>.ics</code> link) from Google Calendar, Outlook, Apple Calendar, Nextcloud, or any iCal-compatible service</li>
<li>Your WordPress timezone must be set correctly (Settings → General → Timezone)</li>
</ul>

Icalviz

Show your real-time Google Calendar availability as a beautiful front-end calendar — no API key, no coding required.

CMSB Kalender vs Icalviz