Function get_tzoffset_from_pytzinfo

numpy/core/src/multiarray/datetime.c:2325–2356

* Gets a tzoffset in minutes by calling the fromutc() function on * the Python datetime.tzinfo object. */

 * the Python datetime.tzinfo object.
 */
NPY_NO_EXPORT int
get_tzoffset_from_pytzinfo(PyObject *timezone_obj, npy_datetimestruct *dts)
{
    PyObject *dt, *loc_dt;
    npy_datetimestruct loc_dts;

    /* Create a Python datetime to give to the timezone object */
    dt = PyDateTime_FromDateAndTime((int)dts->year, dts->month, dts->day,
                            dts->hour, dts->min, 0, 0);
    if (dt == NULL) {
        return -1;
    }

    /* Convert the datetime from UTC to local time */
    loc_dt = PyObject_CallMethod(timezone_obj, "fromutc", "O", dt);
    Py_DECREF(dt);
    if (loc_dt == NULL) {
        return -1;
    }

    /* Convert the local datetime into a datetimestruct */
    if (convert_pydatetime_to_datetimestruct(loc_dt, &loc_dts, NULL, 0) < 0) {
        Py_DECREF(loc_dt);
        return -1;
    }

    Py_DECREF(loc_dt);

    /* Calculate the tzoffset as the difference between the datetimes */
    return (int)(get_datetimestruct_minutes(&loc_dts) -
                 get_datetimestruct_minutes(dts));
}

/*
 * Converts a PyObject * into a datetime, in any of the forms supported.