DateTimeInterface interface stub has no modify method

Relevant: https://chat.stackoverflow.com/transcript/11?m=50929139 I also think it would be nice to have modify method in the interface as at the moment the interface seems pretty useless. I was told this would be BC and we are not going to change it now. On Tue, 1 Dec 2020 at 15:35, Michael Voříšek - ČVUT FEL <vorismi3@fel.cvut.cz> wrote:

On Tue, Dec 1, 2020 at 4:35 PM Michael Voříšek - ČVUT FEL < vorismi3@fel.cvut.cz> wrote:

Yes, this is intentional. The DateTimeInterface interface (has absolutely nothing to do with stubs -- this is the same in PHP 7) only includes the methods that are present in both DateTime and DateTimeImmuatable **with the same behavior**. DateTime::modify() and DateTimeImmutable::modify(), while having the same signature, do completely different things. One performs an in-place modification, while the other doesn't. You should be doing one of two things: 1. Only accept DateTimeImmutable. 2. Accept DateTimeInterface and then use DateTimeImmutable::createFromInterface() to convert it into a DateTimeImmutable. Working on a plain DateTimeInterface only makes sense if you are using the read-only methods, which are the ones that are part of the DateTimeInterface interface. Regards, Nikita