On the Laravel News site there's a new post sharing information about an upcoming upgrade for the framework's date handling. In Laravel 5.8, there's plans to update the Carbon library to v2.

Thanks to Carbon maintainer @kylekatarnls you will be able to use Carbon 1.0 or Carbon 2.0 staring in Laravel 5.8. The update includes the ability to use Carbon immutable and even make your application use CarbonImmutable as the default.

[...] According to the laravel/framework pull request you can choose which class you want for dates “such CarbonImmutable, Chronos or simply DateTime.”

For those that want to transition to using some of the features Carbon v2 provides, they've linked to an upgrade guide and some information about how localization will change as a re result of the upgrade.

On the Laravel News site there's a tutorial posted showing how to work effectively with mutable and immutable DateTime functionality in PHP. The DateTime functionality has long been bundled with the language and offers powerful tools for working with dates, improving on what the basic date function provides.

Mutable dates can be the source of confusion and unexpected bugs in your code. My goal isn’t to tell you that DateTime is evil because it’s mutable, but to consider the tradeoffs and benefits of using mutable versus immutable DateTime objects. Either approach warrants a good test suite and an awareness of how modifier methods affect your date objects.

Until recently, I wasn’t even aware that PHP offers a counterpart to the DateTime class: DateTimeImmutable. The DateTimeIummtable class works just like the DateTime class, except that it never modifies itself, but returns a new object instead. So if you know how to work with DateTime, you immediately can work with DateTimeImmutable.

The article starts by talking about mutable DateTime objects and shows examples of using the Carbon date handling package as a layer on top of PHP's DateTime handling. It includes code examples of mutable objects. It then moves on to the immutable objects, covering the differences between the two complete with code examples. The post ends with a bit more information about mutable vs immutable and links to the Chronos documentation for more information on another date handling library.

Jeff Madsen has a post on his Medium blog sharing some of his thoughts about immutable DateTime types, what the difference is between mutable and immutable and "why you should care".

I’m going to show you the difference between the two using two popular Php DateTime libraries? - Carbon and Chronos, and then demonstrate the danger of using the mutable one of those.

You have probably used Carbon? - ?it is a wonderful library put together by Brian Nesbitt that takes all the pain out of working with dates. It has got one “short-coming”, if you will?- ?it is built on top of the DateTime object.

He gives an example of why this is a problem with Carbon (mutable) and how it's handled differently in Chronos (immutable). He makes the point that, unless your date values are immutable, you don't have any idea of they've changed elsewhere in the processing. He gives a more real-world example of working with immutable objects with a "user" model class and the "name" properties attached to it.

On the SitePoint PHP blog there's a tutorial that's been posted spotlightling a PHP library that can make working with dates and times simpler: Carbon . In this new tutorial they walk you through what the library has to offer and plenty of examples of it in use.

Carbon is a small library for date and time manipulation in PHP. It relies on and extends the core DateTime class, adding helpful methods for a significantly saner experience.

In this article, we’ll take a look at some basic usage examples, and then use it in a real project.

They start with the installation (via Composer) and a few examples of it in use, determining if a given date string is a weekend, in a leap year, etc. They also talk about localization support and working with time intervals. He then gets into the more real-world part of the example, updating the Diffbot client to optionally support Carbon for its date/time handling. He starts with some tests to define how he wants the handling to work and how to use it to parse the date returned from the DiffBot API.