Calendar: Developer Hooks

Plugin paths #

gravityview/calendar/scripts/fullcalendar

Modify the FullCalendar core script used.

gravityview/calendar/scripts/fullcalendar/locales_dir_url

This filter is deprecated: the calendar no longer loads FullCalendar locale files. A callback on the filter still runs, but nothing uses the URL it returns. To change the calendar’s language, see Override the calendar language below.

FullCalendar overrides #

gravityview/calendar/options

Modify all FullCalendar options in an array.

Override the calendar language

The calendar’s language is the feed’s Localization setting, in its Calendar Settings section. A new feed starts at the site’s language when the calendar supports it, and at English otherwise. The gravityview/calendar/default_locale filter changes that starting value: it receives a language code such as en or de and returns the one to use.

To set the language in code instead, change locale in gravityview/calendar/options. The month title, the dates, and the calendar’s own text follow it. The toolbar buttons keep the Localization language unless the same filter also sets buttonText, as in this example for French:

add_filter( 'gravityview/calendar/options', function ( $calendar_options, $form_id, $feed_id ) {
    $calendar_options['locale'] = 'fr';

    // The toolbar labels follow the feed's Localization setting, so set them as well.
    $calendar_options['buttonText'] = array_merge( (array) ( $calendar_options['buttonText'] ?? [] ), [
        'today'        => "Aujourd'hui",
        'dayGridMonth' => 'Mois',
        'timeGridWeek' => 'Semaine',
        'timeGridDay'  => 'Jour',
    ] );

    return $calendar_options;
}, 10, 3 );

add_filter( 'gravityview/calendar/options', function ( $calendar_options, $form_id, $feed_id ) {
    $calendar_options['locale'] = 'fr';

    // The toolbar labels follow the feed's Localization setting, so set them as well.
    $calendar_options['buttonText'] = array_merge( (array) ( $calendar_options['buttonText'] ?? [] ), [
        'today'        => "Aujourd'hui",
        'dayGridMonth' => 'Mois',
        'timeGridWeek' => 'Semaine',
        'timeGridDay'  => 'Jour',
    ] );

    return $calendar_options;
}, 10, 3 );

The keys in buttonText are the toolbar’s view names. A calendar that shows other views, such as listWeek, needs a key for each of them.

Display events as a full-width block

On the grid layout, set eventDisplay to block to show each event as a full-width block with a background color:

add_filter( 'gravityview/calendar/options', function ( $calendar_options, $form_id, $feed_id ) {
    $calendar_options['eventDisplay'] = 'block';
    return $calendar_options;
}, 10, 3 );

add_filter( 'gravityview/calendar/options', function ( $calendar_options, $form_id, $feed_id ) {
    $calendar_options['eventDisplay'] = 'block';
    return $calendar_options;
}, 10, 3 );

Hiding days from other months (showNonCurrentDates)

Here’s an example of modifying the GravityCalendar output to disable showNonCurrentDates, but only for calendar feed #5:

add_filter( 'gravityview/calendar/options', function ( $calendar_options, $form_id, $feed_id ) {
    // Only modify the setting for Calendar #5
    if( 5 !== $feed_id ) {
        return $calendar_options;
    }

    $calendar_options['showNonCurrentDates'] = false;

    return  $calendar_options;
}, 10, 3 );

add_filter( 'gravityview/calendar/options', function ( $calendar_options, $form_id, $feed_id ) {
    // Only modify the setting for Calendar #5
    if( 5 !== $feed_id ) {
        return $calendar_options;
    }

    $calendar_options['showNonCurrentDates'] = false;

    return  $calendar_options;
}, 10, 3 );

Showing times with two-digit minutes

The FullCalendar script displays times in a truncated manner on the month grid view. If you want to force times to be displayed with a 2-digit minute, you can with the filter below.

FullCalendar’s date formatting reference lists every option.

add_filter('gravityview/calendar/options', function ($calendar_options, $form_id, $feed_id ) {
    $calendar_options['eventTimeFormat'] = [
        'hour' => 'numeric',
        'minute' => '2-digit',
        'meridiem' => 'short'
    ];
    return $calendar_options;
}, 10, 3 );

add_filter('gravityview/calendar/options', function ($calendar_options, $form_id, $feed_id ) {
    $calendar_options['eventTimeFormat'] = [
        'hour' => 'numeric',
        'minute' => '2-digit',
        'meridiem' => 'short'
    ];
    return $calendar_options;
}, 10, 3 );

Limiting the Agenda layouts to working hours on weekdays

The Week (Agenda) and Day (Agenda) layouts show all 24 hours, and the week shows all seven days. This code shows 8am to 8pm, Monday to Friday, in both Agenda layouts of one calendar. Replace 5 with the calendar’s ID, shown in the ID column on the All Calendars screen.

/**
 * Shows 8am to 8pm, Monday to Friday, in the Agenda layouts of calendar 5.
 *
 * @param array $calendar_options FullCalendar options.
 * @param int   $form_id          ID of the form the calendar uses.
 * @param int   $feed_id          ID of the calendar.
 *
 * @return array FullCalendar options.
 */
add_filter( 'gravityview/calendar/options', function ( $calendar_options, $form_id, $feed_id ) {
    if ( 5 !== $feed_id ) {
        return $calendar_options;
    }

    $calendar_options['views']['timeGrid']['slotMinTime'] = '08:00:00';
    $calendar_options['views']['timeGrid']['slotMaxTime'] = '20:00:00';
    $calendar_options['views']['timeGrid']['weekends']    = false;

    return $calendar_options;
}, 10, 3 );

/**
 * Shows 8am to 8pm, Monday to Friday, in the Agenda layouts of calendar 5.
 *
 * @param array $calendar_options FullCalendar options.
 * @param int   $form_id          ID of the form the calendar uses.
 * @param int   $feed_id          ID of the calendar.
 *
 * @return array FullCalendar options.
 */
add_filter( 'gravityview/calendar/options', function ( $calendar_options, $form_id, $feed_id ) {
    if ( 5 !== $feed_id ) {
        return $calendar_options;
    }

    $calendar_options['views']['timeGrid']['slotMinTime'] = '08:00:00';
    $calendar_options['views']['timeGrid']['slotMaxTime'] = '20:00:00';
    $calendar_options['views']['timeGrid']['weekends']    = false;

    return $calendar_options;
}, 10, 3 );

Events outside those hours, and events on Saturday and Sunday, don’t appear in the Agenda layouts. The other layouts still show them.

gravityview/calendar/extra_options

Modify extra options used in the plugin’s UI that aren’t standard to FullCalendar.

This is a way to pass additional data to the FullCalendar configuration object in a way that won’t affect initialization. For example, navigateToEvents is a custom calendar option and will throw an error if used to initialize a FullCalendar instance in the UI.

You can use it for similar reasons. For an example, see GravityCalendar event tooltips: what they show and how to change them, which uses it to turn off the event tooltip and to change where it opens.

Rendering & content overrides #

gravityview/calendar/settings/entry_status

Modify the status used to find matching entries. If set to false, no status will be defined, and all entries will be returned.

gravityview/calendar/settings/sort_order

/**
 * Overrides the sort order to be sorted by form field #3 when using Calendar #22
 */
add_filter( 'gravityview/calendar/settings/sort_order', function ( $sort_order, $feed_id, $field_map ) {

    if( 22 !== $feed_id ) {
        return  $sort_order;
    }

    return array(
        'key' => 3,
        'direction' => 'DESC',
    );

}, 10, 3 );

/**
 * Overrides the sort order to be sorted by form field #3 when using Calendar #22
 */
add_filter( 'gravityview/calendar/settings/sort_order', function ( $sort_order, $feed_id, $field_map ) {

    if( 22 !== $feed_id ) {
        return  $sort_order;
    }

    return array(
        'key' => 3,
        'direction' => 'DESC',
    );

}, 10, 3 );

gravityview/calendar/events/source_data

This filter supplies the entries the calendar shows in place of the form’s entries. When it returns any entries, the calendar shows only those and doesn’t read the form.

Example: show an event that isn’t stored in the form

/**
 * Adds an event to calendar 5 that isn't stored as an entry.
 *
 * @param array          $entries   Entries for the calendar. Empty unless another callback added some.
 * @param int            $feed_id   ID of the calendar.
 * @param int|false|null $from_date Start of the dates shown, as a timestamp.
 * @param int|false|null $to_date   End of the dates shown, as a timestamp.
 *
 * @return array Entries for the calendar, each shaped like a Gravity Forms entry.
 */
add_filter( 'gravityview/calendar/events/source_data', function ( $entries, $feed_id, $from_date, $to_date ) {
    if ( 5 !== (int) $feed_id ) {
        return $entries;
    }

    $entries[] = [
        'id'      => 9001,
        'form_id' => 4,
        '1'       => 'Cello, advanced', // Field 1, used in the calendar's Event Title.
        '2'       => '2026-10-20',      // Field 2, the calendar's Start Date.
        '3'       => '10:30',           // Field 3, the calendar's Start Time.
        '4'       => '12:30',           // Field 4, the calendar's End Time.
    ];

    return $entries;
}, 10, 4 );

/**
 * Adds an event to calendar 5 that isn't stored as an entry.
 *
 * @param array          $entries   Entries for the calendar. Empty unless another callback added some.
 * @param int            $feed_id   ID of the calendar.
 * @param int|false|null $from_date Start of the dates shown, as a timestamp.
 * @param int|false|null $to_date   End of the dates shown, as a timestamp.
 *
 * @return array Entries for the calendar, each shaped like a Gravity Forms entry.
 */
add_filter( 'gravityview/calendar/events/source_data', function ( $entries, $feed_id, $from_date, $to_date ) {
    if ( 5 !== (int) $feed_id ) {
        return $entries;
    }

    $entries[] = [
        'id'      => 9001,
        'form_id' => 4,
        '1'       => 'Cello, advanced', // Field 1, used in the calendar's Event Title.
        '2'       => '2026-10-20',      // Field 2, the calendar's Start Date.
        '3'       => '10:30',           // Field 3, the calendar's Start Time.
        '4'       => '12:30',           // Field 4, the calendar's End Time.
    ];

    return $entries;
}, 10, 4 );

Each entry holds its values under the field IDs that the calendar’s settings use. In this example, the calendar’s Start Date is field 2, its Start Time is field 3, its End Time is field 4, and its Event Title is {Lesson:1}. Replace 5 with the calendar’s ID and the field IDs with your own. An array with keys such as title and start shows no event.

gravityview/calendar/events/exclude

Prevent entries from being displayed in the calendar by returning an array of IDs.

gravityview/calendar/events/include

Show these events in the calendar.

gravityview/calendar/events/do_shortcodes

Modify whether to process shortcodes in the event title and event description.

gravityview/calendar/shortcode/render/element_attributes

Feed setting filters #

gravityview/calendar/settings/total-event-limit

Modify the total number of events displayed on a calendar. Events from the form’s entries have no limit by default. Events supplied through gravityview/calendar/events/source_data are limited to 1000. Return 0 or less for no limit.

gravityview/calendar/settings/fields/date

Override the field types shown in the feed configuration when selecting Start Date and End Date.

Allow for text fields to be used in the feed configuration

If you allow entering dates into a text field (not recommended, because the formatting varies), you can use that field as the Start Date or End Date. The code below allows that:

/**
 * Add Text fields to the list of fields to display when selecting Start Date and End Date.
 *
 * @param array $field_types
 *
 * @return array Field types, with "text" added.
 */
add_filter( 'gravityview/calendar/settings/fields/date', function ( $field_types ) {

    $field_types[] = 'text';

    return $field_types;
} );

/**
 * Add Text fields to the list of fields to display when selecting Start Date and End Date.
 *
 * @param array $field_types
 *
 * @return array Field types, with "text" added.
 */
add_filter( 'gravityview/calendar/settings/fields/date', function ( $field_types ) {

    $field_types[] = 'text';

    return $field_types;
} );

gravityview/calendar/settings/fields/time

Override the field types shown in the feed configuration when selecting Start Time and End Time.

gravityview/calendar/settings/fields/location

Override the field types shown in the feed configuration when selecting Event Location.

gravityview/calendar/settings/fields/url

Override the field types shown in the feed configuration when selecting Event URL.

Calendar subscription cache filters #

Subscription calendars (the .ics feed that calendar apps poll) are generated once, stored, and served from that stored copy. The copy is rebuilt when it expires, when the feed is saved, and when entries are added, edited, or deleted. These filters control that behavior.

gk/gravitycalendar/ics-export/cache/enabled

Whether generated subscription calendars are stored and served from the stored copy. Return false to generate the calendar on every request, site-wide or for one feed.

• bool $enabled Whether the generated calendar may be stored. Default true
• int $feed_id The feed being generated

gk/gravitycalendar/ics-export/cache/lifetime

How long a stored subscription calendar is served before it is rebuilt.

• int $lifetime Seconds. Default 3600 (one hour)
• int $feed_id The feed ID

gk/gravitycalendar/ics-export/cache/rebuild-timeout

How long a rebuild may run before its claim is considered abandoned and another request is allowed to rebuild the calendar.

• int $seconds Timeout in seconds. Default 600 (ten minutes)
• int $feed_id The feed ID

Example: serve feed 12 fresh on every request, and keep every other feed’s stored copy for 15 minutes instead of an hour.

add_filter( 'gk/gravitycalendar/ics-export/cache/enabled', function ( $enabled, $feed_id ) {
    return 12 === $feed_id ? false : $enabled;
}, 10, 2 );

add_filter( 'gk/gravitycalendar/ics-export/cache/lifetime', function ( $lifetime, $feed_id ) {
    return 15 * MINUTE_IN_SECONDS;
}, 10, 2 );

add_filter( 'gk/gravitycalendar/ics-export/cache/enabled', function ( $enabled, $feed_id ) {
    return 12 === $feed_id ? false : $enabled;
}, 10, 2 );

add_filter( 'gk/gravitycalendar/ics-export/cache/lifetime', function ( $lifetime, $feed_id ) {
    return 15 * MINUTE_IN_SECONDS;
}, 10, 2 );