@deftypefun {int} {gnutls_x509_crt_set_expiration_time} (gnutls_x509_crt_t @var{cert}, time_t @var{exp_time})
@var{cert}: a certificate of type @code{gnutls_x509_crt_t} 

@var{exp_time}: The actual time

This function will set the time this Certificate will expire.
Setting an expiration time to (time_t)-1 will set
to the no well-defined expiration date value.

@strong{Returns:} On success, @code{GNUTLS_E_SUCCESS}  (0) is returned, otherwise a
negative error value.
@end deftypefun