std::chrono::time_zone::to_sys

template< class Duration >
auto to_sys( const std::chrono::local_time<Duration>& tp ) const
    -> std::chrono::sys_time<std::common_type_t<Duration, std::chrono::seconds>>;

template< class Duration >
auto to_sys( const std::chrono::local_time<Duration>& tp, std::chrono::choose z ) const
    -> std::chrono::sys_time<std::common_type_t<Duration, std::chrono::seconds>>;

Converts the local_time tp in this time zone to the corresponding sys_time.

• If z == std::chrono::choose::earliest, returns the earlier sys_time.
• If z == std::chrono::choose::latest, returns the later sys_time

Return value

The UTC equivalent of tp according to the rules of this time zone.

Exceptions

• std::chrono::ambiguous_local_time if the conversion is ambiguous,
• std::chrono::nonexistent_local_time if tp represents a nonexistent time.

Notes

The precision of the result is at least std::chrono::seconds, and will be finer if the argument has finer precision.

Ambiguous and nonexistent local times can occur as a result of time zone transitions (such as daylight saving time). For example, "2016-03-13 02:30:00" does not exist in the "America/New_York" time zone, while "2016-11-06 01:30:00" in that time zone can correspond to two UTC time points: 2016-11-06 05:30:00 UTC and 2016-11-06 06:30:00 UTC.