zendframework/zf2 — pull request #4717 by marc-mabe (2013-06-24 20:45:49+00:00)
Title: fixes 4684: ExpiresHeader does not accept 0

This will fix #4684

It's a quick fix as with this it isn't possible to generate an expires header with `0` as value but it accepts it as a valid date and converts it internally as `1970-01-01 00:00 UTC` so it will be an valid expired date.