Holiday

Holiday is a library that computes holidays in a very flexible way. It is possible to filter holiday lists by various criteria and format them in different ways. It is easy to add more holiday providers, filters and formatters, so even if this library does not perfectly fit your needs, you can simply extend it.

Requirements

• PHP >= 7.3
• Symfony translator is recommended for translations (built-in translator requires version 4.3+, but can be trivially reimplemented for older versions).

That's it really.

Installation

Install the library using Composer.

composer require umulmrum/holiday

Usage Examples

Simple example:

<?php

require 'vendor/autoload.php';

use Umulmrum\Holiday\HolidayCalculator;
use Umulmrum\Holiday\Provider\Germany\Bavaria;

$holidayCalculator = new HolidayCalculator();
$holidays = $holidayCalculator->calculate(Bavaria::class, 2020);

This results in a HolidayList which contains all holidays for 2020; this list can then be used for output or further computation. Holidays are always computed for one full year and can then be narrowed down using filters.

More complex example:

<?php

require 'vendor/autoload.php';

use Umulmrum\Holiday\HolidayCalculator;
use Umulmrum\Holiday\Filter\IncludeTimespanFilter;
use Umulmrum\Holiday\Formatter\DateFormatter;

$holidayCalculator = new HolidayCalculator();
$holidays = $holidayCalculator->calculate('DE-BY', 2020);
// Apply filters, e.g. restrict to one month.
$firstDay = new \DateTime('2020-12-01');
$lastDay = new \DateTime('2020-12-31');
$holidays = $holidays->filter(new IncludeTimespanFilter($firstDay, $lastDay));
// Format the results.
$formattedHolidays = $holidays->format(new DateFormatter());

This results in an array of date strings. Note that we used the ISO-3166-2 code DE-BY to get the holidays for Bavaria. See section Resolving Holiday Providers below for different ways to request holidays.

There are also some helper methods that simplify some common holiday computations. Using the GetHolidayForMonth helper, the example above can be substituted by this:

<?php

require 'vendor/autoload.php';

use Umulmrum\Holiday\Formatter\DateFormatter;
use Umulmrum\Holiday\Helper\GetHolidaysForMonth;
use Umulmrum\Holiday\Provider\Germany\Bavaria;

$formattedHolidays = (new GetHolidaysForMonth())(Bavaria::class, 2020, 12)->format(new DateFormatter());

One last example shows how to compute all holidays, Saturdays and Sundays in the years 2020 and 2021 for the German state Baden-Wuerttemberg, sort these holidays by date and format the result as JSON (all in 2 lines of code):

<?php

require 'vendor/autoload.php';

use Umulmrum\Holiday\HolidayCalculator;
use Umulmrum\Holiday\Filter\SortByDateFilter;
use Umulmrum\Holiday\Formatter\JsonFormatter;
use Umulmrum\Holiday\Provider\Germany\BadenWuerttemberg;
use Umulmrum\Holiday\Provider\Weekday\Saturdays;
use Umulmrum\Holiday\Provider\Weekday\Sundays;

$calculator = new HolidayCalculator();
$holidays = $calculator->calculate([BadenWuerttemberg::class, Saturdays::class, Sundays::class], [2020, 2021]);
$formattedHolidays = $holidays->filter(new SortByDateFilter())->format(new JsonFormatter());

Detailed Usage

First create a HolidayList for holidays in one or more years by using the HolidayCalculator. Pass one or more holiday providers to the calculator to get holidays for these providers, e.g. a country, a religion or event a specific weekday. HolidayList is basically an augmented array of Holiday objects.

use Umulmrum\Holiday\HolidayCalculator;
use Umulmrum\Holiday\Provider\Luxembourg\Luxembourg;
use Umulmrum\Holiday\Provider\Weekday\Saturdays;
use Umulmrum\Holiday\Provider\Weekday\Sundays;

$calculator = new HolidayCalculator();
$holidays = $calculator->calculate(Luxembourg::class, 2020);

// or multiple providers at once by passing an array of providers
$holidays = $calculator->calculate([Luxembourg::class, Saturdays::class, Sundays::class], 2020);

// or multiple years at once by passing an array of years (can be combined)
$holidays = $calculator->calculate(Luxembourg::class, [2020, 2021]);

See the complete list of built-in providers under src/Provider or use them as examples to create your own. Be aware that a holiday is NOT equivalent to a day off - holidays in the sense of this lib is more of a "special day" as defined by providers, and might be traditional or religious days without impact on working hours. To restrict a HolidayList to days off, use the IncludeTypeFilter as described below in the Filters section.

The HolidayList can then be asked for information or holidays can be added or removed, the list can be filtered or formatted.

// Get the number of holidays in the list. HolidayList also implements \Countable
$holidays->count();

// Get the list of holidays as array. HolidayList also implements \IteratorAggregate
$holidays->getList();
$holidays->getIterator();

// Modify the list.
$holidays->add($anotherHoliday);
$holidays->addAll($anotherHolidayList);
$holidays->removeByIndex(3);
$holidays->replaceByIndex(0, $anotherHoliday);

// Check if a given date is in the list
$holidays->isHoliday(new \DateTime('2020-12-01'));

Resolving Holiday Providers

The examples above already showed two different ways to specify for which region or other "entity" holidays should be calculated. There is also a third way, and complete customization is also possible - let's have a look at all of them:

1. Fully qualified class name:

   $calculator->calculate(\Umulmrum\Holiday\Provider\France\France::class, 2020);

   This is suggested as default, since you only need to remember the region to request and IDEs should provide autocompletion to save keystrokes.

2. Instantiated class:

   $calculator->calculate(new \Umulmrum\Holiday\Provider\Weekday\Sundays(\Umulmrum\Holiday\Constant\HolidayType::DAY_OFF), 2020);

   Use an instantiated class of the same type as you would specify when using way 1. Do this if a provider has constructor arguments, such as additional holiday types as seen in the example (Sundays aren't automatically days off).

3. ISO-3166 names:

   $calculator->calculate('AT-9', 2020); // AT-9 = Vienna in Austria

   Use ISO-3166-1 country codes or ISO-3166-2 region codes e.g. if your application already uses them to simplify integration and decoupling of the Holiday lib. The list of supported countries and regions can be found in src/Resolver/isoData.php. There is a fallback to the base country in case the region code is not found - see the comment in the IsoResolver class for details.

4. Custom

   $calculator = new \Umulmrum\Holiday\HolidayCalculator(new \Umulmrum\Holiday\Resolver\ResolverHandler([new MyCustomResolver()]));

   Use this to add custom resolving logic. ResolverHandler takes an array of ProviderResolverInterfaces (and implements ResolverHandlerInterface, so can even be exchanged with more custom code).

Filters

Use filters to narrow down the list of holidays to the desired subset.

use Umulmrum\Holiday\Constant\HolidayType;
use Umulmrum\Holiday\Filter\IncludeTimespanFilter;
use Umulmrum\Holiday\Filter\IncludeTypeFilter;

// Keep only work-free days (as defined in the provider(s) the list is derived from).
$holidays->filter(new IncludeTypeFilter(HolidayType::DAY_OFF));

/*
 * Filters modify the original list. The following example shows how to chain filters to get holidays with type DAY_OFF
 * in January 2020.
 */
$holidays
    ->filter(new IncludeTimespanFilter(new \DateTime('2020-01-01'), new \DateTime('2020-01-31')))
    ->filter(new IncludeTypeFilter(HolidayType::DAY_OFF))
;

See the complete list of built-in filters under src/Filter or use them as examples to create your own (extend AbstractFilter or implement HolidayFilterInterface).

Formatters

Use formatters to - you guessed it - format HolidayLists and Holidays.

use Umulmrum\Holiday\Formatter\JsonFormatter;

$formattedList = $holidayList->format(new JsonFormatter());

Formatters may return a string or an array of strings.

See the complete list of built-in formatters under src/Formatter or use them as examples to create your own (implement HolidayFormatterInterface).

Holiday Types

A HolidayList contains Holiday objects. Apart from a (technical) name and date, each holiday has one or more types. Return these types as an integer bit mask by calling Holiday::getType(), or ask for specific types using Holiday::hasType().

The type is normally a combination of

• the holiday's origin, e.g. religious or traditional,
• the holiday's legal status (official or not),
• the holiday's impact on working hours (e.g. if it's a full or half day off, if schools or government agencies are closed).

See the HolidayType class for available types. This class also contains translation keys for these types which can then get translated for localized readable names - see e.g. JsonFormatter for details.

Which Holidays are Returned

HolidayCalculator only returns holidays that are legally defined in the scope of the chosen holiday provider, or if there's "secular impact", e.g. it's a day off. This means there are differences between providers; e.g. Easter Sunday is an official holiday in Brandenburg/Germany, so it is included for Brandenburg. In the rest of Germany (as well as most other countries) it is not a holiday as it is a Sunday anyway, and therefore not included as a holiday.

Similarly, Sundays are normally not included if they are no official holidays in the scope of the holiday provider, although they are days off in the Western hemisphere. To find out which days are days off, provide both the respective holiday provider and the one for Sundays (or use GetNoWorkDaysForTimeSpan()).

If your use case requires other holiday lists, consider combining multiple providers (e.g. Switzerland and ChristianHolidays), or remove some using filters (e.g. combine IncludeTypeFilter and InverseFilter) to remove Sundays from Brandenburg lists.

Translations

Some formatters can be initialized with an optional translator. See TranslatorInterface and the translation files under res/trans.

Helpers

To simplify some common holiday-related tasks, see the helpers under src/Helper (e.g. the GetNoWorkDaysForTimeSpan helper takes holiday providers and a timespan and calculates a list of all days off for these arguments).

Supported Calendars

Currently only the Gregorian calendar is supported, for years < 10000.

Supported Countries

(map created by simplemaps.com - licensed under MIT)

• Austria (incl. Burgenland, Carinthia, Lower Austria, Salzburg, Styria, Tyrol, UpperAustria, Vienna, Vorarlberg)
• Belgium
• Brazil
• Denmark
• France (incl. Bas-Rhin, French Guiana, Guadeloupe, Haut-Rhin, Martinique, Moselle, Reunion)
• Germany (incl. Baden-Wuerttemberg, Bavaria, Berlin, Brandenburg, Bremen, Hamburg, Hesse, Lower Saxony, Mecklenburg-Vorpommern, North-rhine Westphalia, Rhineland Palatinate, Saarland, Saxony, Saxony-Anhalt, Schleswig-Holstein, Thuringia)
• Ireland
• Italy (incl. South Tyrol)
• Liechtenstein
• Luxembourg
• Mexico
• The Netherlands
• Poland
• Russia
• Spain (common holidays only yet)
• Switzerland (incl. Aargau, Appenzell-Ausserrhoden, Appenzell-Innerrhoden, Basel Landschaft, Basel Stadt, Bern, Fribourg, Geneva, Glarus, Grisons, Jura, Lucerne, Neuchatel, Nidwalden, Obwalden, Schaffhausen, Schwyz, Solothurn, St Gallen, Thurgau, Ticino, Uri, Valais, Vaud, Zuerich, Zug)
• USA (federal holidays only yet)

To create your own holiday providers have a look at the existing code, it should be self-explanatory. I will happily merge pull requests to support more countries (see below).

Notes on German Holidays

• Easter Sunday/Ostersonntag and Whit Sunday/Pfingstsonntag are not public holidays in most states.
• Every Sunday is a public holiday in Hesse.
• Assumption/Mariä Himmelfahrt is a public holiday in about 1700 of about 2000 communities in Bavaria. This is implemented as a partial holiday, so you might want to add your logic that filters this date.
• In Bavaria schools are closed on Assumption Day and on Repentance and Prayer Day. There is no special handling of this "behavior".
• Corpus Christi/Fronleichnam is a public holiday in some communities in Saxony and Thuringia.
• Regional holidays with traditionally (but not publicly) limited opening hours are not considered yet (e.g. carnival days).
• Some ports at the German Ocean celebrate some holidays as "High Holidays". It is generally not allowed to work on these days, and work time ends at 12 o'clock the day before. This is not considered yet.
• Also there are some quiet days that are not public holidays in various states. This is also not considered yet.
• New states of Germany are treated as if they had always been part of the Federal Republic of Germany. For years before 1990 holidays are therefore not correct.

Notes on Swiss Holidays

• Holidays in Switzerland are really complicated as there is wide fragmentation on if or how holidays are celebrated. The implemented rules are a best guess of what makes sense in the scope of this library (written by someone who isn't from Switzerland). I'm open for improvements.

Notes on Christian Holidays

• Only holidays of Western churches are taken into account.
• Only the most important holidays are taken into account, as interpreted by me (which is most likely far from accurate; please feel free to contribute changes).

Note on Holidays Way in the Past or Future

If computing holidays for past years, be aware that they may not be accurate. All holidays were introduced at some point in time, so this lib might return holidays for years in which they really were not in existence, as well as omit holidays that haven't been celebrated for a long time.

Likewise holidays might of course change in the future. Also, Easter date calculation will change in the far future due to astronomical reasons.

This lib aims to be accurate for "recent" years at least, approximately for years after World War II until present. Again, contributions are welcome.

Versioning

This library follows Semantic Versioning. Everything in the library can be considered the public API except:

• code annotated with @internal,
• tests,
• code that can only be accessed by using reflection (e.g. private methods).

Note that the library is still in a 0.* version which allows the public API to change anytime.

Contribution

Contributions are highly welcome. Please follow these rules when submitting a PR:

• Mimic existing code for style and structure.
• Add unit tests for all of your code.
• Use the Symfony code style (call php-cs-fixer fix in the library root without further arguments).

By submitting a PR you agree that all your contributed code may be used under the MIT license.

How To Add a New Country or Region

• Add a provider for that country or region inside src/Provider/....
• Should you need to add country-specific holiday names, add those to Constant\HolidayName and provide English translations inside umulmrum_holiday.en.xliff.
• Lookup the ISO code for your country or region and add it to Resolver\isoData.
• Provide tests inside tests/Provider/... that ideally cover all edge cases.

License

Holiday is licensed under the MIT License. See LICENSE for details.

In short, this license allows you to use this code for almost anything you like. If you somehow make use of it to suppress, injure, kill, spy, or any other thing considered evil, there is nothing in this license that holds you back. But fuck you anyway.

For all other people I hope this little lib helps you and perhaps even gives you some pleasure.