Calculate the difference between two given dates without using any of the PHP date functions, objects or packages not written by yourself.

This includes:

• DateTime
• IntlGregorianCalendar
• Calendar
• Any composer packages implementing date functions (ie https://packagist.org/search/?q=date)

• Dates will be provided in the format “YYYY/MM/DD” for example “2015/03/21”.
• All dates will be based on the Gregorian calendar.
• There should be a single interface for calculating the difference in the format:

$difference = MyDate::diff($start, $end);

• The return value should be an object in the format:

stdClass {
    int   $years,        // The number of years between the two dates.
    int   $months,       // The number of months between the two dates less the years.
    int   $days,         // The number of days between the two dates less the months and the years.
    int   $total_days,   // The total days between the two dates including the months and years.
    bool  $invert        // true if the the difference is negative (i.e. $start > $end).
}

• You are free to structure the rest of your code however you like and will be asked to explain your decisions.
• Basic unit tests are provided however you are free to add tests to cover anything additional you feel is required.

• Fork and clone this repository
• From the root run composer install
• Start with the src/MyDate.php file and code until you are satisfied
• ZIP up your solution and send it in

Basic unit tests are provided in the tests folder. To run these steps simply run:

phpunit --bootstrap= src/autoload.php tests/MyDateTest.php

If you create new class files be sure to update the src/autoload.php file to load these for the tests.