ng (ISO8601 date and
        ISO8601 time separated by a space). It can be customized using the
        C{timeFormat} attribute, which will be used as input for the underlying
        L{datetime.datetime.strftime} call.

        @type when: C{int}
        @param when: POSIX (ie, UTC) timestamp for which to find the offset.

        @rtype: C{str}
        Né<