QDate Class Reference

#include <qdatetime.h>

List of all members.

---

Detailed Description

The QDate class provides date functions.

A QDate object contains a calendar date, i.e. year, month, and day numbers, in the Gregorian calendar (Julian calendar for dates before 15 October 1582). It can read the current date from the system clock. It provides functions for comparing dates, and for manipulating dates. For example, it is possible to add and subtract days, months, and years to dates.

A QDate object is typically created either by giving the year, month, and day numbers explicitly, or by using the static function currentDate() that creates a QDate object containing the system clock's date. An explicit date can also be set using setDate(). The fromString() function returns a QDate given a string and a date format which is used to interpret the date within the string.

The year(), month(), and day() functions provide access to the year, month, and day numbers. Also, dayOfWeek() and dayOfYear() functions are provided. The same information is provided in textual format by the toString(), shortDayName(), longDayName(), shortMonthName(), and longMonthName() functions.

QDate provides a full set of operators to compare two QDate objects where smaller means earlier, and larger means later.

You can increment (or decrement) a date by a given number of days using addDays(). Similarly you can use addMonths() and addYears(). The daysTo() function returns the number of days between two dates.

The daysInMonth() and daysInYear() functions return how many days there are in this date's month and year, respectively. The isLeapYear() function indicates whether this date is in a leap year.

Note that the Gregorian calendar was introduced at different dates in different countries and regions. QDate uses the Gregorian calendar starting from 15 October 1582, and uses the Julian calendar for dates up to 4 October 1582.

See also:

QTime, QDateTime, QDateEdit, QDateTimeEdit, QCalendarWidget

Definition at line 34 of file qdatetime.h.

Public Member Functions
	QDate ()
	QDate (int y, int m, int d)
bool	isNull () const
bool	isValid () const
int	year () const
int	month () const
int	day () const
int	dayOfWeek () const
int	dayOfYear () const
int	daysInMonth () const
int	daysInYear () const
int	weekNumber (int *yearNum=0) const
QString	toString (Qt::DateFormat f=Qt::TextDate) const
QString	toString (const QString &format) const
bool	setYMD (int y, int m, int d)
bool	setDate (int year, int month, int date)
QDate	addDays (int days) const
QDate	addMonths (int months) const
QDate	addYears (int years) const
int	daysTo (const QDate &) const
bool	operator== (const QDate &other) const
bool	operator!= (const QDate &other) const
bool	operator< (const QDate &other) const
bool	operator<= (const QDate &other) const
bool	operator> (const QDate &other) const
bool	operator>= (const QDate &other) const
int	toJulianDay () const
Static Public Member Functions
static QString	shortMonthName (int month)
static QString	shortDayName (int weekday)
static QString	longMonthName (int month)
static QString	longDayName (int weekday)
static QDate	currentDate ()
static QDate	fromString (const QString &s, Qt::DateFormat f=Qt::TextDate)
static QDate	fromString (const QString &s, const QString &format)
static bool	isValid (int y, int m, int d)
static bool	isLeapYear (int year)
static uint	gregorianToJulian (int y, int m, int d)
static void	julianToGregorian (uint jd, int &y, int &m, int &d)
static QDate	fromJulianDay (int jd)
Private Attributes
uint	jd
Friends
class	QDateTime
class	QDateTimePrivate
Q_CORE_EXPORT QDataStream &	operator<< (QDataStream &, const QDate &)
Q_CORE_EXPORT QDataStream &	operator>> (QDataStream &, QDate &)

---

Constructor & Destructor Documentation

QDate::QDate

(

)

[inline]

Constructs a null date. Null dates are invalid.

See also:

isNull(), isValid()

Definition at line 37 of file qdatetime.h.

Referenced by fromString().

{ jd = 0; }

QDate::QDate	(	int	y,
		int	m,
		int	d
	)

Constructs a date with year y, month m and day d.

If the specified date is invalid, the date is not set and isValid() returns false. Any date before 2 January 4713 B.C. is considered invalid.

Warning:

For historical reasons, if y is in the range 0 to 99, it is interpreted as a year in the range 1900 to 1999. New code should not rely on this behavior as it might be changed in a future release.

See also:

isValid()

Definition at line 230 of file qdatetime.cpp.

References setDate(), and u.

{
    if (uint(y) <= 99u)
        y += 1900;
    setDate(y, m, d);
}

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---

Member Function Documentation

bool QDate::isNull

(

)

const [inline]

Returns true if the date is null; otherwise returns false. A null date is invalid.

See also:

isValid()

Definition at line 40 of file qdatetime.h.

Referenced by QDateTime::isNull(), and isValid().

{ return jd == 0; }

bool QDate::isValid

(

)

const

Returns true if this date is valid; otherwise returns false.

See also:

isNull()

Definition at line 254 of file qdatetime.cpp.

References isNull().

Referenced by QCalendarModel::cellForDate(), QCalendarModel::data(), Q3DateEdit::date(), QCalendarModel::dateForCell(), MySortFilterProxyModel::dateInRange(), QDateTimeEditPrivate::emitSignals(), Q3DateEdit::event(), QCalendarModel::flags(), fmtDateTime(), QSqlDriver::formatValue(), QIBaseDriver::formatValue(), QCalendarView::handleMouseEvent(), QDateTime::isValid(), localToUtc(), QCalendarView::mouseMoveEvent(), QCalendarView::mousePressEvent(), QCalendarView::mouseReleaseEvent(), operator<<(), Q3DateEdit::outOfRange(), QCalendarDelegate::paint(), QDateTimeParser::parse(), QDateTime::QDateTime(), QDateTimeEdit::QDateTimeEdit(), Q3DateEdit::setDate(), QDateTime::setDate(), setDate(), QDateTimeEdit::setDate(), QCalendarWidget::setDateRange(), QDateTimeEdit::setDateRange(), Q3DateEdit::setDay(), QCalendarWidget::setMaximumDate(), QDateTimeEdit::setMaximumDate(), QDateTimeEdit::setMinimumDate(), QCalendarWidget::setMinimumDate(), VariantDelegate::setModelData(), Q3DateEdit::setRange(), QCalendarWidget::setSelectedDate(), QTest::toString(), toString(), QCalendarWidgetPrivate::updateCurrentPage(), and weekNumber().

{
    return !isNull();
}

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int QDate::year

(

)

const

Returns the year of this date. Zero and negative numbers indicate years before 1 A.D. = 1 C.E., such that year 0 is 1 B.C.E., -1 is 2 B.C.E. and so forth.

See also:

month(), day()

Definition at line 268 of file qdatetime.cpp.

References d, getDateFromJulianDay(), jd, m, and y.

Referenced by QCalendarWidgetPrivate::_q_slotChangeDate(), QCalendarModel::cellForDate(), QCalendarWidgetPrivate::createHeader(), QAbstractFormBuilder::createProperty(), QCalendarModel::dateForCell(), dayOfYear(), QODBCResult::exec(), Q3DateEdit::fix(), QIBaseDriver::formatValue(), fromString(), MainWindow::insertCalendar(), localToUtc(), QCalendarView::moveCursor(), operator<<(), QDateTimeParser::parse(), QDateTimeParser::potentialValue(), QCalendarModel::QCalendarModel(), Q3DateEdit::setDate(), QCalendarWidget::setDateRange(), QDateTimeParser::setDigit(), QCalendarWidget::setMaximumDate(), QCalendarWidget::setMinimumDate(), MainWindow::setMonth(), QCalendarWidget::setSelectedDate(), MainWindow::setYear(), QCalendarWidget::showSelectedDate(), QCalendarWidget::showToday(), QLocale::toString(), QDateTime::toString(), toString(), QCalendarWidgetPrivate::updateMonthMenu(), and weekNumber().

{
    int y, m, d;
    getDateFromJulianDay(jd, &y, &m, &d);
    return y;
}

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int QDate::month

(

)

const

Returns the number corresponding to the month of this date, using the following convention:

1 = "January" 2 = "February" 3 = "March" 4 = "April" 5 = "May" 6 = "June" 7 = "July" 8 = "August" 9 = "September" 10 = "October" 11 = "November" 12 = "December"

See also:

year(), day()

Definition at line 297 of file qdatetime.cpp.

References d, getDateFromJulianDay(), jd, m, and y.

Referenced by QCalendarWidgetPrivate::_q_monthChanged(), QCalendarWidgetPrivate::_q_slotChangeDate(), QCalendarWidgetPrivate::_q_yearEditingFinished(), QCalendarModel::cellForDate(), QDateTimeParser::checkIntermediate(), QCalendarWidgetPrivate::createHeader(), QAbstractFormBuilder::createProperty(), QCalendarModel::dateForCell(), QODBCResult::exec(), Q3DateEdit::fix(), QCalendarModel::formatForCell(), QIBaseDriver::formatValue(), fromString(), MainWindow::insertCalendar(), localToUtc(), QCalendarView::moveCursor(), operator<<(), QDateTimeParser::parse(), QCalendarModel::QCalendarModel(), Q3DateEdit::setDate(), QCalendarWidget::setDateRange(), QDateTimeParser::setDigit(), QCalendarWidget::setMaximumDate(), QCalendarWidget::setMinimumDate(), QCalendarWidget::setSelectedDate(), MainWindow::setYear(), QCalendarWidget::showSelectedDate(), QCalendarWidget::showToday(), QDateTime::toString(), QLocale::toString(), toString(), and QCalendarWidgetPrivate::updateMonthMenu().

{
    int y, m, d;
    getDateFromJulianDay(jd, &y, &m, &d);
    return m;
}

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int QDate::day

(

)

const

Returns the day of the month (1 to 31) of this date.

See also:

year(), month(), dayOfWeek()

Definition at line 310 of file qdatetime.cpp.

References d, getDateFromJulianDay(), jd, m, and y.

Referenced by QCalendarWidgetPrivate::_q_yearEditingFinished(), QCalendarModel::cellForDate(), QAbstractFormBuilder::createProperty(), QCalendarModel::data(), QODBCResult::exec(), Q3DateEdit::fix(), QIBaseDriver::formatValue(), fromString(), localToUtc(), operator<<(), QDateTimeParser::parse(), Q3DateEdit::setDate(), QDateTimeParser::setDigit(), MainWindow::setMonth(), MainWindow::setYear(), QDateTimeEditPrivate::stepBy(), QLocale::toString(), QDateTime::toString(), and toString().

{
    int y, m, d;
    getDateFromJulianDay(jd, &y, &m, &d);
    return d;
}

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int QDate::dayOfWeek

(

)

const

Returns the weekday (1 to 7) for this date.

See also:

day(), dayOfYear(), Qt::DayOfWeek

Definition at line 323 of file qdatetime.cpp.

References jd.

Referenced by QCalendarModel::cellForDate(), QCalendarModel::dateForCell(), QDateTimeParser::parse(), QDateTime::toString(), QLocale::toString(), toString(), and weekNumber().

{
    return (jd % 7) + 1;
}

int QDate::dayOfYear

(

)

const

Returns the day of the year (1 to 365) for this date.

See also:

day(), dayOfWeek()

Definition at line 334 of file qdatetime.cpp.

References jd, julianDayFromDate(), and year().

Referenced by weekNumber().

{
    return jd - julianDayFromDate(year(), 1, 1) + 1;
}

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int QDate::daysInMonth

(

)

const

Returns the number of days in the month (28 to 31) for this date.

See also:

day(), daysInYear()

Definition at line 345 of file qdatetime.cpp.

References d, getDateFromJulianDay(), isLeapYear(), jd, m, monthDays, and y.

Referenced by QCalendarModel::cellForDate(), QCalendarModel::dateForCell(), fixedDate(), QCalendarView::moveCursor(), QDateTimeParser::parse(), and QDateTimeEditPrivate::stepBy().

{
    int y, m, d;
    getDateFromJulianDay(jd, &y, &m, &d);
    if (m == 2 && isLeapYear(y))
        return 29;
    else
        return monthDays[m];
}

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int QDate::daysInYear

(

)

const

Returns the number of days in the year (365 or 366) for this date.

See also:

day(), daysInMonth()

Definition at line 361 of file qdatetime.cpp.

References d, getDateFromJulianDay(), isLeapYear(), jd, m, and y.

{
    int y, m, d;
    getDateFromJulianDay(jd, &y, &m, &d);
    return isLeapYear(y) ? 366 : 365;
}

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int QDate::weekNumber

(

int *

yearNumber = 0

)

const

Returns the week number (1 to 53), and stores the year in {yearNumber} unless yearNumber is null (the default).

Returns 0 if the date is invalid.

In accordance with ISO 8601, weeks start on Qt::Monday and the first Qt::Thursday of a year is always in week 1 of that year. Most years have 52 weeks, but some have 53.

{yearNumber} is not always the same as year(). For example, 1 January 2000 has week number 52 in the year 1999, and 31 December 2002 has week number 1 in the year 2003.

Copyright (c) 1989 The Regents of the University of California. All rights reserved.

Redistribution and use in source and binary forms are permitted provided that the above copyright notice and this paragraph are duplicated in all such forms and that any documentation, advertising materials, and other materials related to such distribution and use acknowledge that the software was developed by the University of California, Berkeley. The name of the University may not be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

See also:

isValid()

Definition at line 401 of file qdatetime.cpp.

References dayOfWeek(), dayOfYear(), isLeapYear(), isValid(), len, w, and year().

Referenced by QCalendarModel::data().

{
    if (!isValid())
        return 0;

    int year = QDate::year();
    int yday = dayOfYear() - 1;
    int wday = dayOfWeek();
    if (wday == 7)
        wday = 0;
    int w;

    for (;;) {
        int len;
        int bot;
        int top;

        len = isLeapYear(year) ? 366 : 365;
        /*
        ** What yday (-3 ... 3) does
        ** the ISO year begin on?
        */
        bot = ((yday + 11 - wday) % 7) - 3;
        /*
        ** What yday does the NEXT
        ** ISO year begin on?
        */
        top = bot - (len % 7);
        if (top < -3)
            top += 7;
        top += len;
        if (yday >= top) {
            ++year;
            w = 1;
            break;
        }
        if (yday >= bot) {
            w = 1 + ((yday - bot) / 7);
            break;
        }
        --year;
        yday += isLeapYear(year) ? 366 : 365;
    }
    if (yearNumber != 0)
        *yearNumber = year;
    return w;
}

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QString QDate::shortMonthName

(

int

month

)

[static]

Returns the name of the month using the following convention:

1 = "Jan" 2 = "Feb" 3 = "Mar" 4 = "Apr" 5 = "May" 6 = "Jun" 7 = "Jul" 8 = "Aug" 9 = "Sep" 10 = "Oct" 11 = "Nov" 12 = "Dec"

The month names will be localized according to the system's locale settings.

See also:

toString(), longMonthName(), shortDayName(), longDayName()

Definition at line 475 of file qdatetime.cpp.

References QLocale::monthName(), qWarning(), QLocale::ShortFormat, and QLocale::system().

Referenced by QDateTimeParser::findMonth(), fromString(), QDateTime::fromString(), QDateTimeParser::sectionMaxSize(), QDateTime::toString(), and toString().

{
    if (month < 1 || month > 12) {
        qWarning("QDate::shortMonthName: Parameter out ouf range");
        month = 1;
    }
    return QLocale::system().monthName(month, QLocale::ShortFormat);
}

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QString QDate::shortDayName

(

int

weekday

)

[static]

Returns the name of the weekday using the following convention:

1 = "Mon" 2 = "Tue" 3 = "Wed" 4 = "Thu" 5 = "Fri" 6 = "Sat" 7 = "Sun"

The day names will be localized according to the system's locale settings.

See also:

toString(), shortMonthName(), longMonthName(), longDayName()

Definition at line 538 of file qdatetime.cpp.

References QLocale::dayName(), qWarning(), QLocale::ShortFormat, and QLocale::system().

Referenced by QCalendarModel::dayName(), QDateTimeParser::findDay(), QDateTimeParser::sectionMaxSize(), QDateTime::toString(), and toString().

{
    if (weekday < 1 || weekday > 7) {
        qWarning("QDate::shortDayName: Parameter out of range");
        weekday = 1;
    }
    return QLocale::system().dayName(weekday, QLocale::ShortFormat);
}

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QString QDate::longMonthName

(

int

month

)

[static]

Returns the long name of the month using the following convention:

1 = "January" 2 = "February" 3 = "March" 4 = "April" 5 = "May" 6 = "June" 7 = "July" 8 = "August" 9 = "September" 10 = "October" 11 = "November" 12 = "December"

The month names will be localized according to the system's locale settings.

See also:

toString(), shortMonthName(), shortDayName(), longDayName()

Definition at line 509 of file qdatetime.cpp.

References QLocale::LongFormat, QLocale::monthName(), qWarning(), and QLocale::system().

Referenced by QCalendarWidgetPrivate::createHeader(), QDateTimeParser::findMonth(), MainWindow::insertCalendar(), QCalendarWidget::minimumSizeHint(), QDateTimeParser::sectionMaxSize(), and QCalendarWidgetPrivate::updateHeader().

{
    if (month < 1 || month > 12) {
        qWarning("QDate::longMonthName: Parameter out ouf range");
        month = 1;
    }
    return QLocale::system().monthName(month, QLocale::LongFormat);
}

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QString QDate::longDayName

(

int

weekday

)

[static]

Returns the long name of the weekday using the following convention:

1 = "Monday" 2 = "Tuesday" 3 = "Wednesday" 4 = "Thursday" 5 = "Friday" 6 = "Saturday" 7 = "Sunday"

The day names will be localized according to the system's locale settings.

See also:

toString(), shortDayName(), shortMonthName(), longMonthName()

Definition at line 567 of file qdatetime.cpp.

References QLocale::dayName(), QLocale::LongFormat, qWarning(), and QLocale::system().

Referenced by QCalendarModel::dayName(), QDateTimeParser::findDay(), MainWindow::insertCalendar(), and QDateTimeParser::sectionMaxSize().

{
    if (weekday < 1 || weekday > 7) {
        qWarning("QDate::longDayName: Parameter out of range");
        weekday = 1;
    }
    return QLocale::system().dayName(weekday, QLocale::LongFormat);
}

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QString QDate::toString

(

Qt::DateFormat

format = Qt::TextDate

)

const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Returns the date as a string. The format parameter determines the format of the string.

If the format is Qt::TextDate, the string is formatted in the default way. QDate::shortDayName() and QDate::shortMonthName() are used to generate the string, so the day and month names will be localized names. An example of this formatting is "Sat May 20 1995".

If the format is Qt::ISODate, the string format corresponds to the ISO 8601 extended specification for representations of dates and times, taking the form YYYY-MM-DD, where YYYY is the year, MM is the month of the year (between 01 and 12), and DD is the day of the month between 01 and 31.

If the format is Qt::LocalDate or Qt::SystemLocaleDate, the string format depends on the locale settings of the system. Identical to calling QLocale::system().toString(date, QLocale::ShortFormat). {Qt::LocalDate has been deprecated, please use Qt::SystemLocaleDate instead.}

If the format is Qt::LocaleDate, the string format depends on the default application locale. This is the locale set with QLocale::setDefault(), or the system locale if no default locale has been set. Identical to calling QLocale().toString(date, QLocale::ShortFormat);

If the datetime is invalid, an empty string will be returned.

Warning:

The Qt::ISODate format is only valid for years in the range 0 to 9999. This restriction may apply to Qt::LocalDate as well, depending on the locale settings.

See also:

shortDayName(), shortMonthName()

Definition at line 619 of file qdatetime.cpp.

References QString::arg(), d, day(), dayOfWeek(), QString::fromLatin1(), getDateFromJulianDay(), Qt::ISODate, isValid(), jd, Qt::LocaleDate, m, month(), QString::number(), shortDayName(), QLocale::ShortFormat, shortMonthName(), QLocale::system(), Qt::SystemLocaleDate, Qt::TextDate, QLocale::toString(), y, and year().

Referenced by Window::createDateTimeEdits(), MainWindow::createLetter(), QSqlDriver::formatValue(), operator<<(), Window::setFormatString(), SpreadSheetDelegate::setModelData(), QDateTime::toString(), QTest::toString(), and qdesigner_internal::DateProperty::toString().

{
    if (!isValid())
        return QString();
    int y, m, d;
    getDateFromJulianDay(jd, &y, &m, &d);
    switch (f) {
    case Qt::SystemLocaleDate:
        return QLocale::system().toString(*this, QLocale::ShortFormat);
    case Qt::LocaleDate:
        return QLocale().toString(*this, QLocale::ShortFormat);
    default:
#ifndef QT_NO_TEXTDATE
    case Qt::TextDate:
        {
            return QString::fromLatin1("%0 %1 %2 %3")
                .arg(shortDayName(dayOfWeek()))
                .arg(shortMonthName(m))
                .arg(d)
                .arg(y);
        }
#endif
    case Qt::ISODate:
        {
            if (year() < 0 || year() > 9999)
                return QString();
            QString month(QString::number(m).rightJustified(2, QLatin1Char('0')));
            QString day(QString::number(d).rightJustified(2, QLatin1Char('0')));
            return QString::number(y) + QLatin1Char('-') + month + QLatin1Char('-') + day;
        }
    }
}

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QString QDate::toString

(

const QString &

format

)

const

Returns the date as a string. The format parameter determines the format of the result string.

These expressions may be used:

Expression Output d the day as number without a leading zero (1 to31) dd the day as number with a leading zero (01 to 31) ddd the abbreviated localized day name (e.g. 'Mon' to 'Sun'). Uses QDate::shortDayName(). dddd the long localized day name (e.g. 'QtMonday' to 'QtSunday'). Uses QDate::longDayName(). M the month as number without a leading zero (1-12) MM the month as number with a leading zero (01-12) MMM the abbreviated localized month name (e.g. 'Jan' to 'Dec'). Uses QDate::shortMonthName(). MMMM the long localized month name (e.g. 'January' to 'December'). Uses QDate::longMonthName(). yy the year as two digit number (00 to 99) yyyy the year as four digit number

All other input characters will be ignored. Any sequence of characters that are enclosed in singlequotes will be treated as text and not be used as an expression.

Example format strings (assuming that the QDate is the 20 July 1969):

Format Result dd.MM.yyyy 20.07.1969 ddd MMMM d yy Sun July 20 69 'The day is' dddd The day is Sunday

If the datetime is invalid, an empty string will be returned.

Warning:

This function is only valid for years in the range 0 to 9999.

See also:

QDateTime::toString() QTime::toString()

Definition at line 702 of file qdatetime.cpp.

References fmtDateTime(), and year().

{
    if (uint(year()) > 9999)
        return QString();
    return fmtDateTime(format, 0, this);
}

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bool QDate::setYMD	(	int	y,
		int	m,
		int	d
	)

Sets the date's year y, month m, and day d.

If y is in the range 0 to 99, it is interpreted as 1900 to 1999.

Use setDate() instead.

Definition at line 721 of file qdatetime.cpp.

References setDate().

Referenced by operator>>().

{
    if (uint(y) <= 99)
        y += 1900;
    return setDate(y, m, d);
}

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bool QDate::setDate	(	int	year,
		int	month,
		int	day
	)

Since:

4.2

Sets the date's year, month, and day. Returns true if the date is valid; otherwise returns false.

If the specified date is invalid, the QDate object is set to be invalid. Any date before 2 January 4713 B.C. is considered invalid.

See also:

isValid()

Definition at line 740 of file qdatetime.cpp.

References isValid(), jd, and julianDayFromDate().

Referenced by fixedDate(), QDate(), setYMD(), and strictDate().

{
    if (!isValid(year, month, day)) {
        jd = 0;
    } else {
        jd = julianDayFromDate(year, month, day);
    }
    return jd != 0;
}

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QDate QDate::addDays

(

int

ndays

)

const

Returns a QDate object containing a date ndays later than the date of this object (or earlier if ndays is negative).

See also:

addMonths() addYears() daysTo()

Definition at line 757 of file qdatetime.cpp.

References d, and jd.

Referenced by QDateTime::addDays(), fromDate(), fromTimeStamp(), QCalendarView::moveCursor(), and QDateTime::setTime_t().

{
    QDate d;
    d.jd = jd + ndays;
    return d;
}

QDate QDate::addMonths

(

int

nmonths

)

const

Returns a QDate object containing a date nmonths later than the date of this object (or earlier if nmonths is negative).

See also:

addDays() addYears()

Definition at line 771 of file qdatetime.cpp.

References d, fixedDate(), getDateFromJulianDay(), jd, m, and y.

Referenced by QCalendarWidgetPrivate::_q_monthChanged(), QCalendarWidgetPrivate::_q_nextMonthClicked(), QCalendarWidgetPrivate::_q_prevMonthClicked(), QDateTime::addMonths(), QCalendarModel::cellForDate(), QCalendarModel::dateForCell(), and QCalendarView::moveCursor().

{
    int y, m, d;
    getDateFromJulianDay(jd, &y, &m, &d);

    while (nmonths != 0) {
        if (nmonths < 0 && nmonths + 12 <= 0) {
            y--;
            nmonths+=12;
        } else if (nmonths < 0) {
            m+= nmonths;
            nmonths = 0;
            if (m <= 0) {
                --y;
                m += 12;
            }
        } else if (nmonths - 12 >= 0) {
            y++;
            nmonths -= 12;
        } else if (m == 12) {
            y++;
            m = 0;
        } else {
            m += nmonths;
            nmonths = 0;
            if (m > 12) {
                ++y;
                m -= 12;
            }
        }
    }

    return fixedDate(y, m, d);
}

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QDate QDate::addYears

(

int

nyears

)

const

Returns a QDate object containing a date nyears later than the date of this object (or earlier if nyears is negative).

See also:

addDays(), addMonths()

Definition at line 813 of file qdatetime.cpp.

References d, fixedDate(), getDateFromJulianDay(), jd, m, and y.

Referenced by QDateTime::addYears().

{
    int y, m, d;
    getDateFromJulianDay(jd, &y, &m, &d);
    y += nyears;
    return fixedDate(y, m, d);
}

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int QDate::daysTo

(

const QDate &

d

)

const

Returns the number of days from this date to d (which is negative if d is earlier than this date).

Example:

        QDate d1(1995, 5, 17);  // May 17, 1995
        QDate d2(1995, 5, 20);  // May 20, 1995
        d1.daysTo(d2);          // returns 3
        d2.daysTo(d1);          // returns -3

See also:

addDays()

Definition at line 836 of file qdatetime.cpp.

References d, and jd.

Referenced by QDateTime::daysTo(), localToUtc(), QDateTime::secsTo(), toDate(), toTimeStamp(), QCalendarWidgetPrivate::updateCurrentPage(), and utcToLocal().

{
    return d.jd - jd;
}

bool QDate::operator==

(

const QDate &

d

)

const [inline]

Returns true if this date is equal to d; otherwise returns false.

Definition at line 74 of file qdatetime.h.

References jd.

{ return jd == other.jd; }

bool QDate::operator!=

(

const QDate &

d

)

const [inline]

Returns true if this date is different from d; otherwise returns false.

Definition at line 75 of file qdatetime.h.

References jd.

{ return jd != other.jd; }

bool QDate::operator<

(

const QDate &

d

)

const [inline]

Returns true if this date is earlier than d; otherwise returns false.

Definition at line 76 of file qdatetime.h.

References jd.

{ return jd < other.jd; }

bool QDate::operator<=

(

const QDate &

d

)

const [inline]

Returns true if this date is earlier than or equal to d; otherwise returns false.

Definition at line 77 of file qdatetime.h.

References jd.

{ return jd <= other.jd; }

bool QDate::operator>

(

const QDate &

d

)

const [inline]

Returns true if this date is later than d; otherwise returns false.

Definition at line 78 of file qdatetime.h.

References jd.

{ return jd > other.jd; }

bool QDate::operator>=

(

const QDate &

d

)

const [inline]

Returns true if this date is later than or equal to d; otherwise returns false.

Definition at line 79 of file qdatetime.h.

References jd.

{ return jd >= other.jd; }

QDate QDate::currentDate

(

)

[static]

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Returns the current date, as reported by the system clock.

See also:

QTime::currentTime(), QDateTime::currentDateTime()

Definition at line 891 of file qdatetime.cpp.

References d, julianDayFromDate(), and t.

Referenced by Window::createDateTimeEdits(), MainWindow::createLetter(), QDateTime::currentDateTime(), Q3DateEdit::fix(), MainWindow::insertCalendar(), MainWindow::newLetter(), Q3FtpDTP::parseDir(), QFtpDTP::parseDir(), QCalendarModel::QCalendarModel(), QueryPage::QueryPage(), and QCalendarWidget::showToday().

{
    QDate d;
#if defined(Q_OS_WIN)
    SYSTEMTIME st;
    memset(&st, 0, sizeof(SYSTEMTIME));
    GetLocalTime(&st);
    d.jd = julianDayFromDate(st.wYear, st.wMonth, st.wDay);
#else
    // posix compliant system
    time_t ltime;
    time(&ltime);
    tm *t;

#if !defined(QT_NO_THREAD) && defined(_POSIX_THREAD_SAFE_FUNCTIONS)
    // use the reentrant version of localtime() where available
    tm res;
    t = localtime_r(&ltime, &res);
#else
    t = localtime(&ltime);
#endif // !QT_NO_THREAD && _POSIX_THREAD_SAFE_FUNCTIONS

    d.jd = julianDayFromDate(t->tm_year + 1900, t->tm_mon + 1, t->tm_mday);
#endif
    return d;
}

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QDate QDate::fromString	(	const QString &	string,
		Qt::DateFormat	format = Qt::TextDate
	)			[static]

Returns the QDate represented by the string, using the format given, or an invalid date if the string cannot be parsed.

Note for Qt::TextDate: It is recommended that you use the English short month names (e.g. "Jan"). Although localized month names can also be used, they depend on the user's locale settings.

Warning:

Qt::LocalDate cannot be used here.

Definition at line 932 of file qdatetime.cpp.

References day(), i, Qt::ISODate, Qt::LocalDate, month(), QDate(), qt_shortMonthNames, s, shortMonthName(), strictDate(), Qt::TextDate, and year().

Referenced by convert(), QPSQLResult::data(), QDateTime::fromString(), Q3FtpDTP::parseDir(), QFtpDTP::parseDir(), qDateFromString(), SpreadSheetDelegate::setEditorData(), and VariantDelegate::setModelData().

{
    if ((s.isEmpty()) || (f == Qt::LocalDate))
        return QDate();

    switch (f) {
    case Qt::ISODate:
        {
            int year(s.mid(0, 4).toInt());
            int month(s.mid(5, 2).toInt());
            int day(s.mid(8, 2).toInt());
            if (year && month && day)
                return strictDate(year, month, day);
        }
        break;
    default:
#ifndef QT_NO_TEXTDATE
    case Qt::TextDate:
        {
            /*
              This will fail gracefully if the input string doesn't
              contain any space.
            */
            int monthPos = s.indexOf(QLatin1Char(' ')) + 1;
            int dayPos = s.indexOf(QLatin1Char(' '), monthPos) + 1;
            int yearPos = s.indexOf(QLatin1Char(' '), dayPos) + 1;

            QString monthName(s.mid(monthPos, dayPos - monthPos - 1));
            int month = -1;

            // try English names first
            for (int i = 0; i < 12; i++) {
                if (monthName == QLatin1String(qt_shortMonthNames[i])) {
                    month = i + 1;
                    break;
                }
            }

            // try the localized names
            if (month == -1) {
                for (int i = 0; i < 12; i++) {
                    if (monthName == shortMonthName(i + 1)) {
                        month = i + 1;
                        break;
                    }
                }
            }
            if (month >= 1 && month <= 12) {
                int day = s.mid(dayPos, 2).trimmed().toInt();
                int year = s.mid(yearPos).toInt();
                return strictDate(year, month, day);
            }
        }
#else
        break;
#endif
    }
    return QDate();
}

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QDate QDate::fromString	(	const QString &	string,
		const QString &	format
	)			[static]

Returns the QDate represented by the string, using the format given, or an invalid date if the string cannot be parsed.

These expressions may be used for the format:

Expression Output d The day as a number without a leading zero (1 to 31) dd The day as a number with a leading zero (01 to 31) ddd The abbreviated localized day name (e.g. 'Mon' to 'Sun'). Uses QDate::shortDayName(). dddd The long localized day name (e.g. 'Monday' to 'Sunday'). Uses QDate::longDayName(). M The month as a number without a leading zero (1 to 12) MM The month as a number with a leading zero (01 to 12) MMM The abbreviated localized month name (e.g. 'Jan' to 'Dec'). Uses QDate::shortMonthName(). MMMM The long localized month name (e.g. 'January' to 'December'). Uses QDate::longMonthName(). yy The year as two digit number (00 to 99) yyyy The year as four digit number

All other input characters will be treated as text. Any sequence of characters that are enclosed in single quotes will also be treated as text and will not be used as an expression. For example:

        QDate date = QDate::fromString("1MM12car2003", "d'MM'MMcaryyyy");
        // date is 1 December 2003

If the format is not satisfied, an invalid QDate is returned. The expressions that don't expect leading zeroes (d, M) will be greedy. This means that they will use two digits even if this will put them outside the accepted range of values and leaves too few digits for other sections. For example, the following format string could have meant January 30 but the M will grab two digits, resulting in an invalid date:

        QDate date = QDate::fromString("130", "Md"); // invalid

For any field that is not represented in the format the following defaults are used:

Field Default value Year 1900 Month 1 Day 1

The following examples demonstrate the default values:

        QDate::fromString("1.30", "M.d");           // January 30 1900
        QDate::fromString("20000110", "yyyyMMdd");  // January 10, 2000
        QDate::fromString("20000110", "yyyyMd");    // January 10, 2000

See also:

QDateTime::fromString(), QTime::fromString(), QDate::toString(), QDateTime::toString(), QTime::toString()

Definition at line 1065 of file qdatetime.cpp.

References QVariant::Date, QDateTimeParser::fromString(), and QDateTimeParser::parseFormat().

{
    QDate date;
#ifndef QT_BOOTSTRAPPED
    QDateTimeParser dt(QVariant::Date);
    if (dt.parseFormat(format))
        dt.fromString(string, &date, 0);
#else
    Q_UNUSED(string);
    Q_UNUSED(format);
#endif
    return date;
}

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bool QDate::isValid	(	int	year,
		int	month,
		int	day
	)			[static]

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Returns true if the specified date (year, month, and day) is valid; otherwise returns false.

Example:

        QDate::isValid(2002, 5, 17);  // true
        QDate::isValid(2002, 2, 30);  // false (Feb 30 does not exist)
        QDate::isValid(2004, 2, 29);  // true (2004 is a leap year)
        QDate::isValid(2000, 2, 29);  // true (2000 is a leap year)
        QDate::isValid(2006, 2, 29);  // false (2006 is not a leap year)
        QDate::isValid(2100, 2, 29);  // false (2100 is not a leap year)
        QDate::isValid(1202, 6, 6);   // true (even though 1202 is pre-Gregorian)

See also:

isNull(), setDate()

Definition at line 1100 of file qdatetime.cpp.

References FIRST_DAY, FIRST_MONTH, FIRST_YEAR, isLeapYear(), and monthDays.

{
    if (year < FIRST_YEAR
            || (year == FIRST_YEAR && (month < FIRST_MONTH || month == FIRST_MONTH && day < FIRST_DAY))
            || year == 0) // there is no year 0 in the Julian calendar
        return false;

    // passage from Julian to Gregorian calendar
    if (year == 1582 && month == 10 && day > 4 && day < 15)
        return 0;

    return (day > 0 && month > 0 && month <= 12) &&
           (day <= monthDays[month] || (day == 29 && month == 2 && isLeapYear(year)));
}

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bool QDate::isLeapYear

(

int

year

)

[static]

Returns true if the specified year is a leap year; otherwise returns false.

Definition at line 1122 of file qdatetime.cpp.

Referenced by daysInMonth(), daysInYear(), isValid(), and weekNumber().

{
    if (y < 1582) {
        return qAbs(y) % 4 == 0;
    } else {
        return y % 4 == 0 && y % 100 != 0 || y % 400 == 0;
    }
}

uint QDate::gregorianToJulian	(	int	y,
		int	m,
		int	d
	)			[static]

Definition at line 1138 of file qdatetime.cpp.

References julianDayFromDate().

{
    return julianDayFromDate(y, m, d);
}

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void QDate::julianToGregorian	(	uint	jd,
		int &	y,
		int &	m,
		int &	d
	)			[static]

Definition at line 1150 of file qdatetime.cpp.

References getDateFromJulianDay().

{
    getDateFromJulianDay(jd, &y, &m, &d);
}

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static QDate QDate::fromJulianDay

(

int

jd

)

[inline, static]

Converts the Julian day jd to a QDate.

See also:

toJulianDay()

Definition at line 100 of file qdatetime.h.

References d.

Referenced by QCalendarModel::QCalendarModel().

{ QDate d; d.jd = jd; return d; }

int QDate::toJulianDay

(

)

const [inline]

Converts the date to a Julian day.

See also:

fromJulianDay()

Definition at line 101 of file qdatetime.h.

{ return jd; }

---

Friends And Related Function Documentation

friend class QDateTime [friend]

Definition at line 106 of file qdatetime.h.

friend class QDateTimePrivate [friend]

Definition at line 107 of file qdatetime.h.

QDataStream & operator<<	(	QDataStream &	out,
		const QDate &	date
	)			[friend]

Writes the date to stream out.

See also:

{Format of the QDataStream operators}

Definition at line 2782 of file qdatetime.cpp.

{
    return out << (quint32)(date.jd);
}

QDataStream & operator>>	(	QDataStream &	in,
		QDate &	date
	)			[friend]

Reads a date from stream in into the date.

See also:

{Format of the QDataStream operators}

Definition at line 2795 of file qdatetime.cpp.

{
    quint32 jd;
    in >> jd;
    date.jd = jd;
    return in;
}

---

Member Data Documentation

uint QDate::jd [private]

Definition at line 104 of file qdatetime.h.

Referenced by addDays(), addMonths(), QDateTimePrivate::addMSecs(), addYears(), day(), dayOfWeek(), dayOfYear(), daysInMonth(), daysInYear(), daysTo(), month(), operator!=(), operator<(), operator<=(), operator==(), operator>(), operator>=(), setDate(), toString(), and year().

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The documentation for this class was generated from the following files:

• src/corelib/tools/qdatetime.h
• src/corelib/tools/qdatetime.cpp

---