template<class Duration1, class Duration2, class TimeZonePtr>
bool operator==(const zoned_time<Duration1, TimeZonePtr>& x,
const zoned_time<Duration2, TimeZonePtr>& y);
template<class charT, class traits, class Duration, class TimeZonePtr>
basic_ostream<charT, traits>&
operator<<(basic_ostream<charT, traits>& os,
const zoned_time<Duration, TimeZonePtr>& t);