README

A modern, strongly-typed, immutable iCalendar library for PHP 8.3+.

Implements RFC 5545 (iCalendar), RFC 7986 (new properties), and RFC 5546 (iTIP scheduling).

No stringly-typed array access, no $event['VEVENT']['SUMMARY']. Fluent builders, immutable value objects, typed getters, and lossless round-tripping of anything the library doesn't model.

use Erenav\ICalendar\Component\{Calendar, Event};
use Erenav\ICalendar\Serializer\IcsSerializer;
use Erenav\ICalendar\ValueType\Duration;

$calendar = Calendar::build()
    ->prodId('-//Acme//Booking 1.0//EN')
    ->add(
        Event::build()
            ->uid('booking-42@acme.test')
            ->summary('Sprint Planning')
            ->starts(new DateTimeImmutable('2026-07-01 10:00', new DateTimeZone('UTC')))
            ->lasting(Duration::hours(1))
            ->addAttendee('alice@acme.test')
    )
    ->get();

echo (new IcsSerializer)->serialize($calendar);

📖 New here? The Recipes page has short, copy-paste examples for the most common tasks — start there.

Why this library
Requirements
Installation
Quick start
Building calendars
Serializing to .ics
Parsing .ics
Reading data
Editing immutably
Dates, times & time zones
Durations
Attendees & organizer
Alarms
Recurring events
Time zones
Scheduling (iTIP)
Custom & unknown properties
Strict vs lenient
Error handling
Gotchas & current limitations
Architecture
Testing
Roadmap
License

Why this library

sabre/vobject is the established option, but it leans on stringly-typed array access and mutable objects. erenav/icalendar aims for:

Strong typing — enums for parameters/statuses, dedicated value objects for dates, durations, periods, geo, etc. Illegal states are unconstructable.
Immutability — every component and value is readonly. You mutate through a builder and get a fresh object.
Fluent construction — Event::build()->summary(...)->addAttendee(...)->get().
Lossless round-trips — properties and components it doesn't model are preserved verbatim, so reading and re-writing a third-party .ics never silently drops data.
Zero runtime dependencies.

Requirements

PHP 8.3+
No runtime dependencies (the recurrence engine in phase 2 will add rlanvin/php-rrule)

Installation

composer require erenav/icalendar

Quick start

require 'vendor/autoload.php';

use Erenav\ICalendar\Component\{Calendar, Event};
use Erenav\ICalendar\Parser\Parser;
use Erenav\ICalendar\Serializer\IcsSerializer;
use Erenav\ICalendar\ValueType\Duration;

// Build
$calendar = Calendar::build()
    ->prodId('-//Acme//EN')
    ->add(
        Event::build()
            ->uid('1@acme.test')
            ->summary('Lunch')
            ->starts(new DateTimeImmutable('2026-07-01 12:00', new DateTimeZone('UTC')))
            ->lasting(Duration::hours(1))
    )
    ->get();

// Serialize
$ics = (new IcsSerializer)->serialize($calendar);

// Parse back
$parsed = Parser::lenient()->parseCalendar($ics);
echo $parsed->events()[0]->summary(); // "Lunch"

Building calendars

Calendar::build(), Event::build() and Alarm::build() return mutable builders. Calling ->get() produces the immutable component.

use Erenav\ICalendar\Component\{Calendar, Event};
use Erenav\ICalendar\Parameter\{Role, PartStat};
use Erenav\ICalendar\Property\{EventStatus, Transparency, Classification};
use Erenav\ICalendar\ValueType\Duration;

$event = Event::build()
    ->uid('meeting-42@acme.test')
    ->timestamp(new DateTimeImmutable('now', new DateTimeZone('UTC'))) // DTSTAMP
    ->summary('Sprint Planning, Q3')          // commas/semicolons escaped automatically
    ->description("Agenda:\n- demo\n- retro")
    ->location('Room 4')
    ->url('https://acme.test/meetings/42')
    ->starts(new DateTimeImmutable('2026-07-01 09:30', new DateTimeZone('UTC')))
    ->lasting(Duration::hours(1))             // or ->ends($dateTime)
    ->status(EventStatus::Confirmed)
    ->transparency(Transparency::Opaque)
    ->classification(Classification::Private)
    ->priority(5)
    ->categories('work', 'planning')
    ->color('cornflowerblue')                 // RFC 7986
    ->organizer('boss@acme.test', name: 'The Boss')
    ->addAttendee('alice@acme.test', role: Role::Chair, rsvp: true, name: 'Alice')
    ->addAttendee('bob@acme.test', partStat: PartStat::Accepted)
    ->get();

$calendar = Calendar::build()
    ->prodId('-//Acme//Booking 1.0//EN')      // VERSION defaults to 2.0
    ->name('Team Calendar')                   // RFC 7986
    ->add($event)                             // accepts components or builders
    ->get();

Serializing to `.ics`

use Erenav\ICalendar\Serializer\IcsSerializer;

$ics = (new IcsSerializer)->serialize($calendar);

// Strict mode validates required properties (UID, DTSTAMP, VERSION, PRODID, …)
$ics = (new IcsSerializer(strict: true))->serialize($calendar);

The serializer handles CRLF line endings, 75-octet line folding (UTF-8 safe), TEXT escaping, RFC 6868 parameter encoding, and derives TZID / VALUE / ENCODING parameters from the values themselves.

Parsing `.ics`

use Erenav\ICalendar\Parser\Parser;

$calendar = Parser::lenient()->parseCalendar($icsString); // returns Calendar
$component = Parser::lenient()->parse($icsString);         // returns the root Component

// Strict parsing throws on RFC violations instead of recovering:
$calendar = Parser::strict()->parseCalendar($icsString);

Parsing is lossless (Level-1): unknown properties, unknown components, and unrecognized parameter values are preserved, so serialize(parse($ics)) round-trips without dropping data (see Gotchas for what "Level-1" means exactly).

Reading data

Typed getters read from the underlying model. Optional properties return null.

$event = $calendar->events()[0];

$event->uid();            // ?string
$event->summary();        // ?string  (already unescaped)
$event->description();    // ?string
$event->location();       // ?string
$event->start();          // ?DateTimeValue
$event->end();            // ?DateTimeValue  (computed from DTSTART+DURATION if no DTEND)
$event->duration();       // ?Duration
$event->status();         // ?EventStatus
$event->priority();       // ?int
$event->categories();     // list<string>
$event->organizer();      // ?Organizer
$event->attendees();      // list<Attendee>
$event->alarms();         // list<Alarm>

// Calendar level
$calendar->productId();   // ?string
$calendar->version();     // ?string
$calendar->events();      // list<Event>
$calendar->components();  // list<Component>  (events, time zones, todos, …)

Anything without a dedicated getter is still reachable:

$event->property('X-APPLE-TRAVEL-ADVISORY-BEHAVIOR')?->value()->toString();
$event->hasProperty('RRULE');
foreach ($event->properties as $property) { /* … */ }

Editing immutably

Components are readonly. To change one, get a builder back, tweak it, and rebuild — the original is untouched.

$updated = $event->toBuilder()
    ->summary('Sprint Planning (rescheduled)')
    ->starts(new DateTimeImmutable('2026-07-02 09:30', new DateTimeZone('UTC')))
    ->get();

$event->summary();   // unchanged — original is immutable
$updated->summary(); // "Sprint Planning (rescheduled)"

Dates, times & time zones

iCalendar distinguishes four date/time forms. The DateTimeValue value object models all of them, and is the single source of truth for the TZID / VALUE=DATE parameters.

use Erenav\ICalendar\ValueType\DateTimeValue;

DateTimeValue::utc(new DateTimeImmutable('2026-07-01 10:00', new DateTimeZone('UTC')));
//   → 20260701T100000Z

DateTimeValue::zoned(new DateTimeImmutable('2026-07-01 09:30'), 'America/New_York');
//   → DTSTART;TZID=America/New_York:20260701T093000

DateTimeValue::floating(new DateTimeImmutable('2026-07-01 09:30'));
//   → 20260701T093000   (no zone, "local" time)

DateTimeValue::date(new DateTimeImmutable('2026-07-01'));
//   → DTSTART;VALUE=DATE:20260701   (all-day)

The builder's date setters accept any DateTimeInterface (so Carbon works), or a DateTimeValue when you need an explicit form:

$event = Event::build()
    ->starts($carbonInstance)                                  // inferred form
    ->ends(DateTimeValue::zoned($dt, 'Europe/Paris'))          // explicit form
    ->get();

// All-day event:
$allDay = Event::build()
    ->starts(DateTimeValue::date(new DateTimeImmutable('2026-07-01')))
    ->ends(DateTimeValue::date(new DateTimeImmutable('2026-07-02')))
    ->get();

Durations

Duration is a dedicated value object (not DateInterval) because the iCalendar DURATION type forbids months/years, has a distinct week form, and must be immutable. It bridges to native PHP both ways:

use Erenav\ICalendar\ValueType\Duration;

Duration::hours(1);                 // PT1H
Duration::minutes(-15);             // -PT15M  (negative — e.g. an alarm trigger)
Duration::weeks(2);                 // P2W
Duration::of(days: 1, hours: 6);    // P1DT6H
Duration::parse('PT90M');           // from a string

// Interop (CarbonInterval extends DateInterval, so it works too):
Duration::fromDateInterval(new DateInterval('PT1H'));
Duration::hours(1)->toDateInterval();

Attendees & organizer

addAttendee() builds the ATTENDEE property and its parameters. attendees() returns the raw Property objects (lossless — you get the address and all parameters).

use Erenav\ICalendar\Parameter\{Role, PartStat, CuType};

$event = Event::build()
    ->organizer('boss@acme.test', name: 'The Boss', sentBy: 'mailto:assistant@acme.test')
    ->addAttendee('alice@acme.test', role: Role::Chair, partStat: PartStat::Accepted, rsvp: true, name: 'Alice')
    ->addAttendee('room-a@acme.test', cuType: CuType::Room)
    ->get();

$attendee = $event->attendees()[0];     // a typed Attendee
$attendee->address()->toString();      // "mailto:alice@acme.test"
$attendee->email();                    // "alice@acme.test"
$attendee->role();                     // Role::Chair       (typed)
$attendee->participationStatus();      // PartStat::Accepted
$attendee->commonName();               // "Alice"
$attendee->rsvp();                     // true
$attendee->property;                   // the underlying Property (lossless escape hatch)

Alarms

use Erenav\ICalendar\Component\{Event, Alarm};
use Erenav\ICalendar\Property\AlarmAction;
use Erenav\ICalendar\ValueType\Duration;

$event = Event::build()
    ->uid('1@acme.test')
    ->addAlarm(
        Alarm::build()
            ->action(AlarmAction::Display)
            ->description('Starts in 15 minutes')
            ->trigger(Duration::minutes(-15))   // relative; or pass a DateTimeInterface for absolute
    )
    ->get();

$event->alarms()[0]->action();   // AlarmAction::Display
$event->alarms()[0]->trigger();  // Duration (or DateTimeValue)

Recurring events

Recurrence rules are modelled by the immutable Recurrence value object and built fluently (each modifier returns a new instance):

use Erenav\ICalendar\Recurrence\{Recurrence, Weekday, WeekdayRule};

Recurrence::daily()->times(10);                          // FREQ=DAILY;COUNT=10
Recurrence::weekly()->every(2)->on(Weekday::Monday, Weekday::Wednesday);
Recurrence::monthly()->on(new WeekdayRule(Weekday::Friday, -1)); // last Friday of the month
Recurrence::yearly()->until(new DateTimeImmutable('2030-01-01', new DateTimeZone('UTC')));
Recurrence::parse('FREQ=WEEKLY;BYDAY=MO,WE');           // from an RRULE string

Attach one to an event, with optional exception (EXDATE) and extra (RDATE) dates:

use Erenav\ICalendar\ValueType\DateTimeValue;

$event = Event::build()
    ->uid('standup@acme.test')
    ->starts(DateTimeValue::zoned(new DateTimeImmutable('2026-07-01 09:30'), 'America/New_York'))
    ->recurrence(Recurrence::weekly()->on(Weekday::Monday, Weekday::Wednesday))
    ->addExceptionDate(new DateTimeImmutable('2026-12-25 09:30', new DateTimeZone('America/New_York')))
    ->get();

$event->isRecurring();     // true
$event->recurrenceRule();  // ?Recurrence

Expand the concrete occurrences in a window (RRULE + RDATE − EXDATE, DST-aware for IANA zones — wall-clock time is preserved across transitions):

$from = new DateTimeImmutable('2026-07-01');
$to   = new DateTimeImmutable('2026-08-01');

foreach ($event->occurrencesBetween($from, $to) as $occurrence) {
    echo $occurrence->format('Y-m-d H:i'); // DateTimeImmutable
}

Expansion wraps rlanvin/php-rrule behind a RecurrenceExpander interface — pass your own implementation to occurrencesBetween() to swap the engine.

Modified & cancelled instances (`RECURRENCE-ID`)

A recurring series can have individual instances overridden by a second VEVENT with the same UID plus a RECURRENCE-ID. Expand at the calendar level to resolve those — Calendar::occurrencesBetween() returns rich Occurrence objects (the effective event per instance), applying modifications and dropping cancellations:

foreach ($calendar->occurrencesBetween($from, $to) as $occurrence) {
    $occurrence->start;        // DateTimeImmutable (may differ from the slot if moved)
    $occurrence->recurrenceId; // the original slot in the series
    $occurrence->event;        // the master, or the override VEVENT for this instance
    $occurrence->isOverride;   // true if a RECURRENCE-ID override applied
}

(Event::occurrencesBetween() expands a single event and returns bare instants; Calendar::occurrencesBetween() is the override-aware version across the whole calendar.)

Time zones

Zoned date-times reference a TZID. For portability, a calendar can carry its own VTIMEZONE definitions so clients don't need to know the zone. withTimeZones() generates them automatically from PHP's tz database for every IANA zone your events use:

$calendar = Calendar::build()
    ->prodId('-//Acme//EN')
    ->add(
        Event::build()->uid('1@acme')
            ->starts(DateTimeValue::zoned(new DateTimeImmutable('2026-07-01 09:30'), 'America/New_York')),
    )
    ->get()
    ->withTimeZones(); // prepends a correct VTIMEZONE with STANDARD/DAYLIGHT + RRULEs

$calendar->timeZones();          // list<TimeZone>
$calendar->timeZones()[0]->tzid(); // "America/New_York"

Parsed VTIMEZONE blocks are first-class TimeZone components with typed Observance children:

$tz = $calendar->timeZones()[0];
foreach ($tz->observances() as $observance) {
    $observance->isDaylight();        // bool
    $observance->offsetTo();          // ?UtcOffset
    $observance->recurrenceRule();    // ?Recurrence
}

You can also generate one directly: (new TimeZoneGenerator())->forIana('Europe/Paris').

Scheduling (iTIP)

Build RFC 5546 scheduling messages — invitations, replies, cancellations — each with the correct METHOD and required properties, via ITip:

use Erenav\ICalendar\Scheduling\{ITip, ITipValidator};
use Erenav\ICalendar\Parameter\PartStat;

$request = ITip::request($event);                                      // organizer invites attendees
$reply   = ITip::reply($event, 'alice@acme.test', PartStat::Accepted); // attendee responds
$cancel  = ITip::cancel($event);                                       // + STATUS:CANCELLED, SEQUENCE++
$publish = ITip::publish([$eventA, $eventB]);                          // a non-interactive feed

$request->schedulingMethod(); // Method::Request   (typed METHOD getter)

Validate a message against its method's constraints:

$validator = new ITipValidator();

$validator->isValid($request);     // bool
$validator->validate($request);    // list<string> of problems (empty = valid)
$validator->assertValid($request); // throws SchedulingException if invalid

In the Laravel package, attaching an iTIP calendar advertises the method in the MIME type (text/calendar; method=REQUEST), so mail clients treat it as an invitation.

Custom & unknown properties

Add arbitrary properties with ->property() (it appends, so it can repeat):

$event = Event::build()
    ->uid('1@acme.test')
    ->property('X-ACME-ROOM-ID', '4')
    ->get();

When parsing, anything not modelled is preserved verbatim as a RawValue (and unknown components become a GenericComponent), then re-emitted unchanged:

$event->property('X-ACME-ROOM-ID')?->value()->toString(); // "4"
// VTIMEZONE / VTODO / VJOURNAL etc. survive as GenericComponent in $calendar->components()

Strict vs lenient

Both the parser and serializer have a strict mode. Lenient is the default, because real-world .ics files frequently bend the RFC.

Mode	Parser	Serializer
Lenient (default)	Recovers from violations; unparseable values become `RawValue`	Emits whatever is present
Strict	Throws `ParseException` on violations	Throws `MissingPropertyException` for missing required properties

Parser::strict()->parseCalendar($ics);          // validate input
(new IcsSerializer(strict: true))->serialize($c); // validate output before sending

Error handling

Every exception implements Erenav\ICalendar\Exception\ICalendarException, so you can catch the whole family at once.

use Erenav\ICalendar\Exception\{ICalendarException, ParseException, InvalidValueException, MissingPropertyException};

try {
    $calendar = Parser::strict()->parseCalendar($ics);
} catch (ParseException $e) {
    // malformed input in strict mode
} catch (ICalendarException $e) {
    // any other library error
}

InvalidValueException — building an illegal value (bad duration, out-of-range geo, …).
ParseException — malformed input (strict parsing only).
MissingPropertyException — required property absent (strict serialization only).

Gotchas & current limitations

You must set UID (and usually DTSTAMP) yourself. They are not auto-generated. $event->uid() returns null if absent. Use strict serialization to catch this.
Use the calendar-level expander for overrides. Event::occurrencesBetween() expands one event in isolation and ignores RECURRENCE-ID overrides. To honour modified/cancelled instances, expand the whole calendar with Calendar::occurrencesBetween(). Note: RANGE=THISANDFUTURE overrides are treated as single-instance for now.
Custom (non-IANA) VTIMEZONE resolution. Zoned date-times with standard IANA ids (America/New_York) expand DST-correctly, and withTimeZones() generates portable VTIMEZONE blocks for them. A TZID that exists only as a VTIMEZONE block in the file (not a PHP zone) is preserved and readable as a typed TimeZone, but is still treated as UTC for instant math — resolving offsets from custom definitions is deferred.
"Level-1" round-trip ≠ byte-identical. serialize(parse($ics)) never loses data and preserves property order within a component, but it canonicalizes output (line folding position, parameter ordering, escaping). Byte-for-byte fidelity (Level-2) is a future option, not a current guarantee.
Immutability surprise: builder methods that read like mutations (addAttendee) mutate the builder; the produced component is immutable. Edit an existing component via ->toBuilder().
No Laravel glue here. The framework integration (erenav/laravel-icalendar) is a separate package (phase 4). This core has zero framework dependencies.

Architecture

A layered, immutable object model. The canonical state of every component is its ordered property bag, which is what makes lossless round-tripping possible.

Builder      (mutable, fluent)        →  produces  →  Component (immutable)
Component    (Composite: Calendar ▸ Event ▸ Alarm)
  └ holds → PropertyBag (ordered, preserves unknowns)
Property     (name + typed values + parameters)
  ├ value  → ValueType (DateTimeValue, Duration, Period, TextValue, RawValue, …)
  └ params → Parameter (Role, PartStat, … enums + RawParameter fallback)

Parser:     text → unfold → split content lines → hydrate values → assemble tree
Serializer: Component → content lines → fold → text   (Strategy: Ics, future jCal/xCal)

Patterns in use: Composite (component tree), Builder (fluent construction), Strategy (Serializer interface), Factory (value-type construction), and a pipeline parser. See docs/PHASE-1-SPEC.md for the full design and decision record.

Testing

composer install
composer test          # or: vendor/bin/phpunit

The suite is split into tests/Unit (per-class) and tests/Integration (serializer + round-trip). Round-trip stability is asserted as a fixed point: serialize(parse(x)) equals serialize(parse(serialize(parse(x)))).

Roadmap

Phase	Scope	Status
1	Core model, parse/serialize, Level-1 round-trip (RFC 5545 + 7986)	✅ done
2	Recurrence + time zones — `occurrencesBetween()`, `RECURRENCE-ID` overrides, `VTIMEZONE` generation/typed components	✅ done
3	iTIP scheduling (RFC 5546) — METHOD, message builders, validation	✅ done
4	`erenav/laravel-icalendar` — service provider, facade, Eloquent mapping, feeds, Artisan, notifications	✅ released separately
5	jCal/xCal serializers, custom-`VTIMEZONE` offset resolution, byte-fidelity round-trip	someday

License

MIT

vanere/icalendar

包简介

关键字：

README 文档

README

Table of contents

Why this library

Requirements

Installation

Quick start

Building calendars

Serializing to `.ics`

Parsing `.ics`

Reading data

Editing immutably

Dates, times & time zones

Durations

Attendees & organizer

Alarms

Recurring events

Modified & cancelled instances (`RECURRENCE-ID`)

Time zones

Scheduling (iTIP)

Custom & unknown properties

Strict vs lenient

Error handling

Gotchas & current limitations

Architecture

Testing

Roadmap

License

统计信息

GitHub 信息

其他信息

vanere/icalendar

包简介

关键字：

README 文档

README

Table of contents

Why this library

Requirements

Installation

Quick start

Building calendars

Serializing to .ics

Parsing .ics

Reading data

Editing immutably

Dates, times & time zones

Durations

Attendees & organizer

Alarms

Recurring events

Modified & cancelled instances (RECURRENCE-ID)

Time zones

Scheduling (iTIP)

Custom & unknown properties

Strict vs lenient

Error handling

Gotchas & current limitations

Architecture

Testing

Roadmap

License

统计信息

GitHub 信息

其他信息

Serializing to `.ics`

Parsing `.ics`

Modified & cancelled instances (`RECURRENCE-ID`)