Rewrite constructors to use "static"? about date-time

[BenMorel]

Hi, sorry for the late reply.

I'm not fond of allowing subclassing in my libraries, unless some class is designed specifically for this purpose. Actually, I might even make the classes final at some point, for 2 reasons:

• it adds a constraint for backward compatibility
• I generally find that subclassing a library's classes does not make a good design: instead, if extensibility is required, an interface should be explicitly provided for this purpose; if not, then composition should be favoured over inheritance.

I'd rather then implement what you think is missing from the library (in this case, a custom format method), so I will close this issue as a duplicate of #3, which is asking for a custom format method as well.

As a final note, did you see that __toString() actually returns YYYY-mm-dd? So you should be able to use (string) $date and be set.