自学教程：C++ weekday函数代码示例

/*----------------------------------------------------------------------* * Convert the given DST change rule to a time_t value                  * * for the given year.                                                  * *----------------------------------------------------------------------*/time_t Timezone::toTime_t(TimeChangeRule r, int yr){    tmElements_t tm;    time_t t;    uint8_t m, w;            //temp copies of r.month and r.week    m = r.month;    w = r.week;    if (w == 0) {            //Last week = 0        if (++m > 12) {      //for "Last", go to the next month            m = 1;            yr++;        }        w = 1;               //and treat as first week of next month, subtract 7 days later    }    tm.Hour = r.hour;    tm.Minute = 0;    tm.Second = 0;    tm.Day = 1;    tm.Month = m;    tm.Year = yr - 1970;    t = makeTime(tm);        //first day of the month, or first day of next month for "Last" rules    t += (7 * (w - 1) + (r.dow - weekday(t) + 7) % 7) * SECS_PER_DAY;    if (r.week == 0) t -= 7 * SECS_PER_DAY;    //back up a week if this is a "Last" rule    return t;}

inline void page_addSchedule() {  static schedule s; //Schedule to be added  static int value = 0;  if(pre_page != ADD_SCHEDULE) {    PTLS("Page Add Schedule");    pre_page = ADD_SCHEDULE;     lcd.cursor();      //Need to reintialize everytime we enter the page but not every refresh    s.day = weekday();    s.hour = hour();    s.minute = minute();    s.temperature = temperature_sensor;    value = 0;  }  String t = getTimeString(s);  lcd.print(F("Add: "));  lcd.print(t);  lcd.setCursor(0,1);  lcd.print(F("Temp: "));  lcd.print(s.temperature);  if (button_input == PLUS_UP || button_input == PLUS_HOLD) {    if (value == 0) {      s.day++;      if (s.day >= 8) s.day = 1;    } else if (value == 1) {      s.hour++;      if (s.hour >= 24) s.hour = 0;    } else if (value == 2) {      s.minute++;      if (s.minute >= 60) s.minute = 0;    } else if (value == 3) {      s.temperature++;      if (s.temperature >= 99)         s.temperature = 99;    }  }  else if (button_input == MINUS_UP || button_input == MINUS_HOLD) {    if (value == 0) {      s.day--;      if (s.day <= 0) s.day = 7;    } else if (value == 1) {      s.hour--;      if (s.hour >= 24) s.hour = 23;    } else if (value == 2) {      s.minute--;      if (s.minute >= 60) s.minute = 59;    } else if (value == 3) {      s.temperature--;      if (s.temperature <= 32 || s.temperature >= 99)         s.temperature = 32;    }  } else if (button_input == MODE_UP)  {    value += 1;    value = value % 4;  } else if (button_input == SET_UP) {    node_add(s);    switchPage(LIST_MODE);  }}

static void date_data_func(GtkTreeViewColumn *col,			   GtkCellRenderer *renderer,			   GtkTreeModel *model,			   GtkTreeIter *iter,			   gpointer data){	int val;	struct tm *tm;	time_t when;	char buffer[40];	gtk_tree_model_get(model, iter, DIVE_DATE, &val, -1);	/* 2038 problem */	when = val;	tm = gmtime(&when);	snprintf(buffer, sizeof(buffer),		"%s, %s %d, %d %02d:%02d",		weekday(tm->tm_wday),		monthname(tm->tm_mon),		tm->tm_mday, tm->tm_year + 1900,		tm->tm_hour, tm->tm_min);	g_object_set(renderer, "text", buffer, NULL);}

String getTimeString(time_t t = now()){  // String holder to return  String dateStr;  byte _day = weekday(t);  byte sub1 = _day * 3;  byte sub2 = sub1 + 3;  dateStr = dayShortNames_P.substring(sub1, sub2);    //Example "Sun "  dateStr.concat(" ");  int _hour = hour(t);  if(_hour < 10) {    dateStr.concat(" ");  }  dateStr.concat(_hour); // EX: "Sun 10"  dateStr.concat(":");  // EX: "Sun 10:"    int _minute = minute(t);  if(_minute < 10) {    dateStr.concat("0");  }  dateStr.concat(_minute); // EX: "Sun 10:1"  dateStr.concat(":"); // EX: "Sun 10:1:"    int _second = second(t);  if(_second < 10) {    dateStr.concat("0");  }  dateStr.concat(_second); // EX: "Sun 10:1:20"    return dateStr;}

/* Compute the day number of Easter Sunday in Julian Calendar */static inteasterodn(int y){	/*	 * Table for the easter limits in one metonic (19-year) cycle. 21	 * to 31 is in March, 1 through 18 in April. Easter is the first	 * sunday after the easter limit.	 */	int     mc[] = {5, 25, 13, 2, 22, 10, 30, 18, 7, 27, 15, 4,		    24, 12, 1, 21, 9, 29, 17};	/* Offset from a weekday to next sunday */	int     ns[] = {6, 5, 4, 3, 2, 1, 7};	date	dt;	int     dn;	/* Assign the easter limit of y to dt */	dt.d = mc[y % 19];	if (dt.d < 21)		dt.m = 4;	else		dt.m = 3;	dt.y = y;	/* Return the next sunday after the easter limit */	dn = ndaysj(&dt);	return (dn + ns[weekday(dn)]);}

void show_dive_info(struct dive *dive){	struct tm *tm;	const char *text;	char buffer[80];	/* dive number and location (or lacking that, the date) go in the window title */	tm = gmtime(&dive->when);	text = dive->location;	if (!text)		text = "";	if (*text) {		snprintf(buffer, sizeof(buffer), "Dive #%d - %s", dive->number, text);	} else {		snprintf(buffer, sizeof(buffer), "Dive #%d - %s %02d/%02d/%04d at %d:%02d",			dive->number,			weekday(tm->tm_wday),			tm->tm_mon+1, tm->tm_mday,			tm->tm_year+1900,			tm->tm_hour, tm->tm_min);	}	text = buffer;	if (!dive->number)		text += 10;     /* Skip the "Dive #0 - " part */	gtk_window_set_title(GTK_WINDOW(main_window), text);	SET_TEXT_ENTRY(divemaster);	SET_TEXT_ENTRY(buddy);	SET_TEXT_ENTRY(location);	gtk_text_buffer_set_text(notes, dive && dive->notes ? dive->notes : "", -1);}

Date::weekday Date::day_of_week() const {	// see wikipedia	static std::array<const int, 12> const t = { { 0, 3, 2, 5, 0, 3, 5, 1, 4, 6, 2, 4 } };    int y=year;    int m=month;    y -= m < 3;    return weekday( (y + y/4 - y/100 + y/400 + t[m-1] + day +6) % 7);}

int main(){	printf("%s/n",weekday(3));//	strcpy(week(3),"Fengjie");	//printf("%s/n",week(3));		showweekday(3);	return 0;}

int meetup_day_of_month(int year, int month, char *descriptor, char *day) {  int offset = offset_for_descriptor(descriptor, year, month);  int first_weekday = weekday(year, month, offset);  int target_weekday = weekday_for_day(day);  if (days_in_month(year, month) < offset)    return 0;  return offset + (target_weekday - first_weekday + 7) % 7;}

void SchedulerJobInstance::calculateNextRunTime() const {	QDateTime nextRun = runTimeToday();	nextRun.setDate(QDate::currentDate().addDays( (weekday() + 1) - QDate::currentDate().dayOfWeek() ));	if (nextRun < QDateTime::currentDateTime()) {		nextRun = nextRun.addDays(7);	}	d->nextRunTime = nextRun;}

void loop() {  delay(250);  if (now() != prevDisplay) { // update the display only if time has changed    if (timeStatus() != timeNotSet) {      DayWeekNumber(year(), month(), day(), weekday());      digitalClockDisplayLCD();      prevDisplay = now();    }  }}

void headers_init(void){  int i, wd;  char *cur_dh = day_headings, *cur_j_dh = j_day_headings;  strcpy(day_headings,"");  strcpy(j_day_headings,"");#ifdef HAVE_LANGINFO_H# define weekday(wd)	nl_langinfo(ABDAY_1+wd)#else# define weekday(wd)	_time_info->abbrev_wkday[wd]#endif  for(i = 0 ; i < 7 ; i++ ) {     ssize_t space_left;     wd = (i + weekstart) % 7;     if (i)        strcat(cur_dh++, " ");     space_left = sizeof(day_headings) - (cur_dh - day_headings);     if(space_left <= 2)        break;     cur_dh += center_str(weekday(wd), cur_dh, space_left, 2);     if (i)        strcat(cur_j_dh++, " ");     space_left = sizeof(j_day_headings) - (cur_j_dh - j_day_headings);     if(space_left <= 3)        break;     cur_j_dh += center_str(weekday(wd), cur_j_dh, space_left, 3);  }#undef weekday  for (i = 0; i < 12; i++) {#ifdef HAVE_LANGINFO_H     full_month[i] = nl_langinfo(MON_1+i);#else     full_month[i] = _time_info->full_month[i];#endif  }}

/* ----------------------------------------------------------------- */int congesmobstr(int jy, char string[])/* ----------------------------------------------------------------- */{int jm,jd; char st[32];double tj,rh,rm,rs;static char *day[7]={"Dim","Lun","Mar","Mer","Jeu","Ven","Sam"};rh=12.0; rm=rs=0.0;easter(jy,&jm,&jd);tj=gregjd(jy,jm,jd,rh,rm,rs)+1.0;jdgreg(tj,&jy,&jm,&jd,&rh,&rm,&rs);sprintf(string,"Paques: %04d.%02d.%02d(%s)",jy,jm,jd,day[weekday(tj)]);tj=gregjd(jy,jm,jd,rh,rm,rs)+38.0;jdgreg(tj,&jy,&jm,&jd,&rh,&rm,&rs);sprintf(st," Ascension: %04d.%02d.%02d(%s)",jy,jm,jd,day[weekday(tj)]); strcat(string,st);tj=gregjd(jy,jm,jd,rh,rm,rs)+11.0;jdgreg(tj,&jy,&jm,&jd,&rh,&rm,&rs);sprintf(st," Pentecote: %04d.%02d.%02d(%s)",jy,jm,jd,day[weekday(tj)]); strcat(string,st);return(0);}

static void ServeEventPage(FILE * stream_file){	ServeHeader(stream_file, 200, "OK", false);	freeMemory();	const time_t timeNow = nntpTimeServer.LocalNow();	fprintf_P(stream_file, PSTR("<h1>%d Events</h1><h3>%02d:%02d:%02d %d/%d/%d (%d)</h3>"), iNumEvents, hour(timeNow), minute(timeNow), second(timeNow),			year(timeNow), month(timeNow), day(timeNow), weekday(timeNow));	for (uint8_t i = 0; i < iNumEvents; i++)		fprintf_P(stream_file, PSTR("Event [%02d] Time:%02d:%02d(%d) Command %d data %d,%d<br/>"), i, events[i].time / 60, events[i].time % 60, events[i].time,				events[i].command, events[i].data[0], events[i].data[1]);}

//////////////////////////////////////////////////////////////////////////////////////////////////// check if system date is valid and send the date header.//////////////////////////////////////////////////////////////////////////////////////////////////void ESP8266WebServerEx::sendDateHeader(char* buf) {  time_t t = now();  // if time is accurate, then try to send a Date header Wed, 15 Nov 1995 06:25:24 GMT  if ( year(t)>2015 ) {    char dow[5];      strncpy(dow,dayShortStr(weekday(t)),4);    dow[3] = 0;    sprintf(buf,"%s, %02u %s %04u %02u:%02u:%02u GMT",dow,day(t),monthShortStr(month(t)),year(t),hour(t),minute(t),second(t));    sendHeader("Date",buf);  } }

QString get_dive_date_string(timestamp_t when){	struct tm tm;	utc_mkdate(when, &tm);	return translate("gettextFromC", "%1, %2 %3, %4 %5:%6")		.arg(weekday(tm.tm_wday))		.arg(monthname(tm.tm_mon))		.arg(tm.tm_mday)		.arg(tm.tm_year + 1900)		.arg(tm.tm_hour, 2, 10, QChar('0'))		.arg(tm.tm_min, 2, 10, QChar('0'));}

void update_dive_info(struct dive *dive){	struct tm *tm;	char buffer[80];	char *text;	flush_dive_info_changes();	buffered_dive = dive;	if (!dive) {		gtk_label_set_text(GTK_LABEL(divedate), "no dive");		gtk_label_set_text(GTK_LABEL(divetime), "");		gtk_label_set_text(GTK_LABEL(depth), "");		gtk_label_set_text(GTK_LABEL(duration), "");		return;	}	tm = gmtime(&dive->when);	snprintf(buffer, sizeof(buffer),		"%s %02d/%02d/%04d",		weekday(tm->tm_wday),		tm->tm_mon+1, tm->tm_mday, tm->tm_year+1900);	gtk_label_set_text(GTK_LABEL(divedate), buffer);	snprintf(buffer, sizeof(buffer),		"%02d:%02d:%02d",		tm->tm_hour, tm->tm_min, tm->tm_sec);	gtk_label_set_text(GTK_LABEL(divetime), buffer);	snprintf(buffer, sizeof(buffer),		"%d ft",		to_feet(dive->maxdepth));	gtk_label_set_text(GTK_LABEL(depth), buffer);	snprintf(buffer, sizeof(buffer),		"%d min",		dive->duration.seconds / 60);	gtk_label_set_text(GTK_LABEL(duration), buffer);	*buffer = 0;	if (dive->watertemp.mkelvin)		snprintf(buffer, sizeof(buffer),			"%d C",			to_C(dive->watertemp));	gtk_label_set_text(GTK_LABEL(temperature), buffer);	text = dive->location ? : "";	gtk_entry_set_text(location, text);	gtk_label_set_text(GTK_LABEL(locationnote), text);	text = dive->notes ? : "";	gtk_text_buffer_set_text(notes, text, -1);}

    weekday weekday::operator++(int)    {        const int index = m_index;        if (m_index < 7)        {            ++m_index;        } else {            m_index = 1;        }        return weekday(index);    }

void digitalClockDisplayLCD() {  // digital clock display of the time  // Serial /w Debug  sprintf(buffer, "$FT,Y0,X0#%04d-%02d-%02d ", year(), month(), day());  Serial.print(buffer);  sprintf(buffer, "$FT,Y1,X0#%s W%02d D%03d", dow2String(weekday()), WN, DN);  Serial.print(buffer);  sprintf(buffer, "$Y5,X0#%02d:%02d:", hour(), minute());  Serial.print(buffer);  sprintf(buffer, "$FN,Y5,X35#%02d", second());  Serial.print(buffer);  Serial.print(F("$FT#"));  // I2C LCD  LcdSetCursor(0, 0);  sprintf(buffer, "%04d-%02d-%02d %s", year(), month(), day(),          dow2String(weekday()));  LcdPrint(buffer);  sprintf(buffer, "%02d:%02d:%02d W%02d %03d", hour(), minute(), second(), WN,          DN);  LcdSetCursor(0, 1);  LcdPrint(buffer);}

void loop(){	// digital clock display of the time	sprintf(msg_buff,"%02d:%02d:%02d  %s",hour(),minute(),second(),  dayStr(weekday()));		sprintf(msg_buff,"%s %d %s %d/r/n",msg_buff, day(),monthStr(month()), year());	//Send the data	uart_printf(msg_buff);	// 1 sec delay   delay(1000);}

/** * Display Date and Time with 'hh:mm:ss <CompleteNameDayWeek> dd <CompleteNameMonth> YYYY' format */void longStrFormat_Display(){	timeComplete_Display();	Serial.print(" ");  Serial.print(dayStr(weekday()));  Serial.print(" ");  Serial.print(day());  Serial.print(" ");  Serial.print(monthStr(month()));  Serial.print(" ");  Serial.print(year());}

void J1ClockKit::Crown::load( tmElements_t &tm ) {    this->timeElements.Second = tm.Second;    this->timeElements.Minute = tm.Minute;    this->timeElements.Hour   = tm.Hour;    this->timeElements.Day    = tm.Day;    this->timeElements.Month  = tm.Month;    this->timeElements.Year   = tm.Year;        time_t t = makeTime( tm );    this->timeElements.Wday   = weekday( t );        this->field = (tmByteFields) min( max( (int)this->field, (int)tmMinute ), (int)tmYear );    this->prepare();}

int main(){char * monad  = monthName(4);printf("%s", monad); //int leapyear = isLeapYear(1990); //printf("%d", leapyear); //system("pause");  char *svar = weekday(0);  printf("%s", svar);  system("pause");}

EXPORT ER dt_gmtime_us( SYSTIM_U tim_u, struct tm* result ){	SYSTIM_U rem = tim_u;	int d, i, md;	if (tim_u < 0) {		return EX_OVERFLOW;	}	result->tm_isdst = 0;	result->tm_usec = (rem % 1000000);	rem /= 1000000;	result->tm_sec = (rem % 60);	rem /= 60;	result->tm_min = (rem % 60);	rem /= 60;	result->tm_hour = (rem % 24);	rem /= 24;	d = rem;	result->tm_wday = weekday(d);	d += daysbefore1985;	result->tm_year = -1900 + 1;	result->tm_year += 400 * (d / days400);	d %= days400;	result->tm_year += 100 * (d / days100);	d %= days100;	result->tm_year += 4 * (d / days4);	d %= days4;	result->tm_year += (d / days1);	d %= days1;	result->tm_yday = d;	for (i = 0; i < 12; i++) {		md = (i == 1 && isleap(result->tm_year)) ? 29 : _dt_mdays[i];		if (d < md) {			break;		}		d -= md;	}	result->tm_mon = i;	result->tm_mday = 1 + d;	return E_OK;}

void printTime(time_t t, char *tz) {    sPrintI00(hour(t));    sPrintDigits(minute(t));    sPrintDigits(second(t));    Serial.print(' ');    Serial.print(weekday(t));    Serial.print(' ');    sPrintI00(day(t));    Serial.print(' ');    Serial.print(month(t));    Serial.print(' ');    Serial.print(year(t));    Serial.print(' ');    Serial.print(tz);    Serial.println();}

/* 	HTTP response sending a code 200 OK response.*/void http_response_ok(FILE *resp, char *cont, int size){	struct tm *st;	st = get_time();	fprintf(resp, "HTTP/1.1 200 OK/r/n");	fprintf(resp, "Date: %s, %i %s %i %i:%i:%i GMT/r/n", weekday(st->tm_wday), 															st->tm_mday, month(st->tm_mon),															(st->tm_year + 1900), st->tm_hour,															st->tm_min, st->tm_sec);	fprintf(resp, "Content-Type: %s/r/nContent-Length: %i/r/n/r/n", cont, size);	return;}

uint8_t Timer::isSummerTime(){	time_t t = mRtc.get() + TIMEZONE_SHIFT_SECONDS;		uint8_t m = month(t);		if(m > 10 || m < 3)	{		return 0;	}	else if(m > 3 && m < 10)	{		return 1;	}	else	{		uint8_t w = weekday(t);				// otestovat posledni nedeli v mesici		if(day(t) + 7 - w < 31)		{			return m == 3 ? 0 : 1;		}		else		{			// nedele - otestovat cas			if(w == 1)			{				if(m == 3)				{					// brezen po druhe hodine					return ( hour(t) > 2 ? 1 : 0);				}				else				{					// rijen po treti hodine					return ( hour(t) > 2 ? 0 : 1);									}			}			else			{				return m == 3 ? 1 : 0;			}		}	}}

void TimeState::renderClockType1(){   Serial.println(F("render time type 1"));  _screen->clearDisplay();  _screen->setTextSize(5);  _screen->setCursor(0, 0);  _screen->setTextWrap(false);  int8_t hour_time = hour();  if(hour_time==0)    hour_time = (uint8_t) 12;  else if(hour_time>=13)    hour_time -= (uint8_t) 12;      if(hour_time<=9)  {    _screen->setCursor(30, 0);    _screen->print(hour_time);  }  else    _screen->print(hour_time);      _screen->setCursor(50, 0);  _screen->print(":");  _screen->setCursor(70, 0);  int8_t minute_time = minute();    if(minute_time<=9){     _screen->print("0");    _screen->setCursor(99, 0);    _screen->print(minute_time);  }  else    _screen->print(minute_time);          _screen->setTextSize(2);  char *wkdy[7] = {"SUN", "MON", "TUE", "WED", "THR", "FRI", "SAT"};  _screen->setCursor(5, 43);  _screen->print(wkdy[weekday()-1]);  _screen->setCursor(60, 43);  _screen->print(month());  _screen->setCursor(78, 43);  _screen->print("/");  _screen->setCursor(95, 43);  _screen->print(day());  _screen->display();}