rem: if(t.is_utc == 1){
add: if(t.is_utc == 1 || t.is_date == 1){
context: short icaltime_day_of_week(struct icaltimetype t){    time_t tt = icaltime_as_timet(t);    struct tm *tm;    if(t.is_utc == 1){	tm = gmtime(&tt);    } else {	tm = localtime(&tt);    }    return tm->tm_wday+1;}