README

BusinessDays is a set of tools for dealing with date calculations when certain (non-business/holiday) days don't count.

This package contains two calculators, FastForwarder and Rewinder, plus a set of filters that can be used with them.

FastForwarder is configured with a day count (N) and a set of callbacks defining what isn't a business day, Once configured, provide it with a start date and it'll return a date that is the first business day at least N business days in the future. Rewinder does the same thing, except working in the opposite temporal direction.

The start date passed into the calculators can be a DateTime or DateTimeImmutable, or a subclass thereof. The value returned will be a clone of whatever was passed in, with its timestamp updated.

This library should conform to PSRs 1, 2 and 4, and requires PHP 5.5 or newer (5.6 recommended). 5.6 is the oldest version of the runtime that has automated tests running.

Install

Via Composer

$ composer require iansltx/business-days

If you don't want Composer, you may download the source zipball directly from GitHub and load it using a PSR-4 compliant autoloader. If you don't have such an autoloader, require autoload.php to get one that works for this library.

Usage

Filters

Calculators (FastForwarder and Rewinder) evaluate filter functions/methods/closures to see whether a given date should be classified as a business day or not. You can provide a closure directly, or use one of the convenience methods to compose a filter more quickly.

The convenience methods simply wrap either functions from StaticFilter or create closures via FilterFactory. Either of these filter utility classes may be used standalone to filter DateTime objects. Additionally, these two filter classes provide more filters than are exposed via the convenience methods on FastForwarder/Rewinder, so check them before rebuilding a filter definition from scratch.

Note that filters requiring numeric input have internal checks that require an explicit int cast for all parameters. Also, while skipWhen filters are executed on-add to check argument and return types, non-closure arguments are allowed, so you can use object methods, utility functions or global functions can be used as filters in addition to closures.

Let's set up a FastForwarder, add some filters, and do some calculations...

use iansltx\BusinessDays\FilterFactory;
use iansltx\BusinessDays\StaticFilter;

// set up the instance with a day count
$ff = new iansltx\BusinessDays\FastForwarder(10);

// add a closure-based filter
$ff->skipWhen(function (\DateTimeInterface $dt) { //
    return $dt->format('m') == 12 && $dt->format('d') == 25;
}, 'christmas');

// define a closure from the filter factory, then pass it in
$dayAfterChristmasFriday = FilterFactory::monthAndDayOnDayOfWeek(12, 26, 5);
$ff->skipWhen($dayAfterChristmasFriday, 'day_after_christmas_friday');

// convenience method; saved to filter slot 'weekend'
$ff->skipWhenWeekend();

// overwrites 'weekend' slot with an identical call
$ff->skipWhen(['iansltx\BusinessDays\StaticFilter', 'isWeekend'], 'weekend');

// use some other convenience methods, this time pulling from FilterFactory and using method chaining
$ff->skipWhenNthDayOfWeekOfMonth(3, 1, 2, 'presidents_day') // third Monday of February
   ->skipWhenNthDayOfWeekOfMonth(4, 4, 11, 'thanksgiving') // fourth Thursday of November
   ->skipWhenMonthAndDay(1, 1) // auto-named to md_1_1 since a filter name wasn't provided
   ->skipWhen([StaticFilter::class, 'isGoodFriday'], 'good_friday')
   ->skipWhen([StaticFilter::class, 'isEasterMonday'], 'easter_monday');

// calculate some dates
echo $ff->exec(new \DateTime('2015-11-20 09:00:00'))->format('Y-m-d H:i:s'); // 2015-12-07 09:00:00
echo $ff->exec(new \DateTimeImmutable('2015-02-12 09:00:00'))->format('Y-m-d H:i:s'); // 2015-02-27 09:00:00

NOTE: Fractional days are rounded up to the next whole day amount; e.g. 2.5 days will be treated as 3.

Exporting/Importing Filter Sets

The list of filters associated with a given calculator may be dumped as an array via getSkipWhenFilters(). This array can be set as filter storage for another calculation class when that class is created, so a set of filters only needs to be defined once.

Some notes on this functionality:

1. Any filters added after construction won't propagate to the calculation object that you got the original filter set from.
2. Passing in a set of filters at construction time will not run argument and return type tests on filters contained therein.

With that, let's copy our filters to a new Rewinder, which as its name suggests goes in the opposite direction, and calculate a few more dates.

// you could also create a FastForwarder with a negative day count with the same effect
$rw = new iansltx\BusinessDays\Rewinder(2, $ff->getSkipWhenFilters());

echo $rw->exec(new \DateTime('2015-02-10 09:00:00'))->format('Y-m-d H:i:s'); // 2015-02-06 09:00:00
echo $rw->exec(new \DateTime('2015-02-18 09:00:00'))->format('Y-m-d H:i:s'); // 2015-02-13 09:00:00

For More Info

For more information on filter arguments etc., take a look at the source. All methods and classes have docblocks. The callable-based syntax of skipWhen() allows for arbitrarily complex definitions of whether a date should be skipped, as can be seen in more complex filters like isEasterMonday.

Testing

$ composer test

humbug.json is included if you want to do mutation testing with Humbug. Currently, not all mutations are caught; PRs are welcome to help rectify this issue. composer test only runs PHPUnit tests.

Contributing

Please see CONTRIBUTING for details. Additional static filters/filter factories are welcome!

Security

If you discover any security related issues, please email iansltx@gmail.com instead of using the issue tracker.

Credits

• Ian Littman
• All Contributors

License

This library is BSD 2-clause licensed. Please see License File for more information.