Question

PHP has no problem with this code:

    interface IDateTimeProvider
    {
        public function date($format);
        public function time();
    }

    class DateTimeProvider implements IDateTimeProvider
    {
        public function date($format)
        {
            return date($format);
        }
        public function time()
        {
            return time();
        }
    }

The date() and time() functions are being defined in that class… so as long as I keep it within a class, I can name my functions with pre-existing PHP functions like date(), time() or ob_start()?

Answer 1

You can do it within classes because their real name, in memory will be like IDateTimeProvider::date. This is called wrapping.

If you want to get them out of a class, you have to use namespaces like that :

namespace MyNamespace;
function time(){
    return \time();
 }

and in another file you will use it with \MyNamespace\time();

For the given functions, it is quite useless and I will remember you that DateTime exists in PHP and is far more powerful than timestamp and his ecosystem.