np_datetime_strings.c

....
/*
 * Wraps `localtime` functionality for multiple platforms. This
 * converts a time value to a time structure in the local timezone.
 *
 * Returns 0 on success, -1 on failure.
 */
static int get_localtime(NPY_TIME_T *ts, struct tm *tms) {
    char *func_name = "<unknown>";
#if defined(_WIN32)
/*#if defined(_MSC_VER) && (_MSC_VER >= 1400)*/
    if (localtime_s(tms, ts) != 0) {
        func_name = "localtime_s";
        goto fail;
    }
/*#elif defined(__GNUC__) && defined(NPY_MINGW_USE_CUSTOM_MSVCR)
    if (_localtime64_s(tms, ts) != 0) {
        func_name = "_localtime64_s";
        goto fail;
    }
#else
    struct tm *tms_tmp;
    localtime_r(ts, tms_tmp);
    if (tms_tmp == NULL) {
        func_name = "localtime";
        goto fail;
    }
    memcpy(tms, tms_tmp, sizeof(struct tm));
#endif
#else
    if (localtime_r(ts, tms) == NULL) {
        func_name = "localtime_r";
        goto fail;
    }*/
#endif

....