a = icaltime_convert_to_zone(a_in, icaltimezone_get_utc_timezone()); b = icaltime_convert_to_zone(b_in, icaltimezone_get_utc_timezone());
a = icaltime_convert_to_zone(a_in, tz); b = icaltime_convert_to_zone(b_in, tz);
icaltime_compare_date_only(const struct icaltimetype a_in, const struct icaltimetype b_in){    int retval;    struct icaltimetype a, b;    a = icaltime_convert_to_zone(a_in, icaltimezone_get_utc_timezone());    b = icaltime_convert_to_zone(b_in, icaltimezone_get_utc_timezone());    if (a.year > b.year)	retval = 1;    else if (a.year < b.year)	retval = -1;    else if (a.month > b.month)	retval = 1;    else if (a.month < b.month)	retval = -1;    else if (a.day > b.day)	retval = 1;    else if (a.day < b.day)	retval = -1;    else	retval = 0;    return retval;}