zoned_time& operator=( const zoned_time& other ) = default;

zoned_time& operator=( const std::chrono::sys_time<Duration>& other );

zoned_time& operator=( const std::chrono::local_time<Duration>& other );

1) Defaulted copy assignment operator. Copy-assigns both the stored time point and the stored time zone pointer. zoned_time has no move assignment operator; a move is a copy.

2) Assigns other to the stored time point. The time zone pointer is unchanged. After this call, get_sys_time() == other.

3) Converts other to a std::chrono::sys_time as if by zone->to_sys(other) (where zone is the non-static data member holding the stored time zone pointer) and assigns the result to the stored time point. The time zone pointer is unchanged. After this call, get_local_time() == other.