tz1.c

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/*
 * Copyright (C) 1995.  Bill Brown <brown@gis.uiuc.edu> & Michael Shapiro
 *
 * This program is free software under the GPL (>=v2)
 * Read the file GPL.TXT coming with GRASS for details.
 */
#include <grass/datetime.h>


static int have(int x, const DateTime * dt)
{
    return datetime_is_between(x, dt->from, dt->to);
}


int datetime_check_timezone(const DateTime * dt, int minutes)
{
    if (!datetime_is_absolute(dt))
        return datetime_error(-1, "datetime not absolute");
    if (!have(DATETIME_MINUTE, dt))
        return datetime_error(-2, "datetime has no minute");
    if (!datetime_is_valid_timezone(minutes))
        return datetime_error(-3, "invalid datetime timezone");

    return 0;
}


int datetime_get_timezone(const DateTime * dt, int *minutes)
{
    int stat;

    stat = datetime_check_timezone(dt, dt->tz);
    if (stat == 0)
        *minutes = dt->tz;

    return stat;
}


int datetime_set_timezone(DateTime * dt, int minutes)
{
    int stat;

    stat = datetime_check_timezone(dt, minutes);
    if (stat == 0)
        dt->tz = minutes;

    return stat;
}

int datetime_unset_timezone(DateTime * dt)
{
    dt->tz = -9999;

    return 0;
}


int datetime_is_valid_timezone(int minutes)
{
    return (minutes >= -720 && minutes <= 780);
}