[ Guido]

Why is this needed? When would a real app use %Z%z? [in strftime]

I've seen it often, and I'm not even a timezone wonk ;-) "The problem" it solves is for programmers who deal with lots of timezones. The name alone is ambiguous in some cases, and so is the offset alone. The offset alone is enough to convert that single instance to UTC, but that's not the only thing someone seeing the output may want to know (else nobody would ever display the name).