27 Time library [time]

27.10 Time zones [time.zone]

27.10.1 In general [time.zone.general]

[time.zone] describes an interface for accessing the IANA Time Zone database described in RFC 6557, that interoperates with sys_­time and local_­time.
This interface provides time zone support to both the civil calendar types ([time.cal]) and to user-defined calendars.