Function mktime_z 

pub unsafe extern "C" fn mktime_z(
    tz: TimezoneT,
    tmp: *const Tm,
) -> TimeT

Convert local time Tm to system time using passed-in time zone.

Rust interface for the C function:

time_t mktime_z(timezone_t restrict, struct tm *restrict);

This acts like mktime except it uses the passed in TimezoneT instead of the shared global configuration.