The QDate class provides date functions. More...

#include <qdatetime.h>

Public Member Functions
	QDate ()

	QDate (int y, int m, int d)

virtual	~QDate ()

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

virtual QString	monthName (int month) const

virtual QString	dayName (int weekday) const

QString	toString () const

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

QDate	addDays (int days) const

int	daysTo (const QDate &) const

bool	operator== (const QDate &d) const

bool	operator!= (const QDate &d) const

bool	operator< (const QDate &d) const

bool	operator<= (const QDate &d) const

bool	operator> (const QDate &d) const

bool	operator>= (const QDate &d) const

Static Public Member Functions
static QDate	currentDate ()

static bool	isValid (int y, int m, int d)

static bool	leapYear (int year)

Static Protected Member Functions
static uint	greg2jul (int y, int m, int d)

static void	jul2greg (uint jd, int &y, int &m, int &d)

Private Attributes
uint	jd

Static Private Attributes
static const char *const	monthNames []

static const char *const	weekdayNames []

Friends
class	QDateTime

Q_EXPORT QDataStream &	operator<< (QDataStream &, const QDate &)

Q_EXPORT QDataStream &	operator>> (QDataStream &, QDate &)

Detailed Description

The QDate class provides date functions.

A QDate object contains a calendar date, i.e. year, month, and day numbers in the modern western (Gregorian) calendar. It can read the current date from the system clock. It provides functions for comparing dates and for manipulating a date by adding a number of days.

A QDate object is typically created either by giving the year, month and day numbers explicitly, or by using the static function currentDate(), which makes a QDate object which contains the system's clock date. An explicit date can also be set using setYMD().

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(), dayName(), and monthName() functions.

QDate provides a full set of operators to compare two QDate objects. A date is considered smaller than another if it is earlier than the other.

The date a given number of days later than a given date can be found using the addDays() function. Correspondingly, the number of days between two dates can be found using the daysTo() function.

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

Note that QDate may not be used for date calculations for dates in the remote past, i.e. prior to the introduction of the Gregorian calendar. This calendar was adopted by England Sep. 14. 1752 (hence this is the earliest valid QDate), and subsequently by most other western countries, until 1923.

The end of time is reached around 8000AD, by which time we expect Qt to be obsolete.

See also: QTime, QDateTime

Definition at line 50 of file qdatetime.h.

Constructor & Destructor Documentation

QDate::QDate ( )

inline

Constructs a null date. Null dates are invalid.

See also: isNull(), isValid()

Definition at line 53 of file qdatetime.h.

53 { jd=0; } // set null date

QDate::jd

uint jd

Definition: qdatetime.h:95

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

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

y must be in the range 1752-ca. 8000, m must be in the range 1-12, and d must be in the range 1-31. Exception: if y is in the range 0-99, it is interpreted as 1900-1999.

See also: isValid()

Definition at line 155 of file qdatetime.cpp.

 {
     jd = 0;
     setYMD( y, m, d );
 }

virtual QDate::~QDate ( )

inlinevirtual

Definition at line 55 of file qdatetime.h.

55 {}

Member Function Documentation

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: daysTo()

Definition at line 370 of file qdatetime.cpp.

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

QDate QDate::currentDate ( )

static

Returns the current date, as reported by the system clock.

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

Definition at line 437 of file qdatetime.cpp.

 {
 #if defined(_OS_WIN32_)
 
     SYSTEMTIME t;
     GetLocalTime( &t );
     QDate d;
     d.jd = greg2jul( t.wYear, t.wMonth, t.wDay );
     return d;
 
 #else
 
     time_t ltime;
     time( &ltime );
     tm *t = localtime( &ltime );
     QDate d;
     d.jd = greg2jul( t->tm_year + 1900, t->tm_mon + 1, t->tm_mday );
     return d;
 
 #endif
 }

int QDate::day ( ) const

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

See also: year(), month(), dayOfWeek()

Definition at line 215 of file qdatetime.cpp.

 {
     int y, m, d;
     jul2greg( jd, y, m, d );
     return d;
 }

QString QDate::dayName ( int weekday ) const

virtual

Returns the name of the weekday.

Weekday 1 == "Mon", day 2 == "Tue" etc.

See also: toString(), monthName()

Definition at line 302 of file qdatetime.cpp.

 {
 #if defined(CHECK_RANGE)
     if ( weekday < 1 || weekday > 7 ) {
         qWarning( "QDate::dayName: Parameter out of range." );
         weekday = 1;
     }
 #endif
     // ### Remove the fromLatin1 during localization
     return QString::fromLatin1(weekdayNames[weekday-1]);
 }

int QDate::dayOfWeek ( ) const

Returns the weekday (Monday=1 .. Sunday=7) for this date.

See also: day(), dayOfYear()

Definition at line 228 of file qdatetime.cpp.

 {
     return (((jd+1) % 7) + 6)%7 + 1;
 }

int QDate::dayOfYear ( ) const

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

See also: day(), dayOfWeek()

Definition at line 239 of file qdatetime.cpp.

 {
     return jd - greg2jul(year(), 1, 1) + 1;
 }

int QDate::daysInMonth ( ) const

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

See also: day(), daysInYear()

Definition at line 250 of file qdatetime.cpp.

 {
     int y, m, d;
     jul2greg( jd, y, m, d );
     if ( m == 2 && leapYear(y) )
         return 29;
     else
         return monthDays[m];
 }

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 266 of file qdatetime.cpp.

 {
     int y, m, d;
     jul2greg( jd, y, m, d );
     return leapYear(y) ? 366 : 365;
 }

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

See also: addDays()

Definition at line 392 of file qdatetime.cpp.

 {
     return d.jd - jd;
 }

uint QDate::greg2jul	(	int	y,
		int	m,
		int	d
	)

staticprotected

Definition at line 504 of file qdatetime.cpp.

 {
     uint c, ya;
     if ( y <= 99 )
         y += 1900;
     if ( m > 2 ) {
         m -= 3;
     } else {
         m += 9;
         y--;
     }
     c = y;                                      // NOTE: Sym C++ 6.0 bug
     c /= 100;
     ya = y - 100*c;
     return 1721119 + d + (146097*c)/4 + (1461*ya)/4 + (153*m+2)/5;
 }

bool QDate::isNull ( ) const

inline

Returns TRUE if the date is null. A null date is invalid.

See also: isValid()

Definition at line 57 of file qdatetime.h.

57 { return jd == 0; }

QDate::jd

uint jd

Definition: qdatetime.h:95

bool QDate::isValid ( ) const

Returns TRUE if this date is valid.

See also: isNull()

Definition at line 177 of file qdatetime.cpp.

 {
     return jd >= FIRST_DAY;
 }

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

static

Returns TRUE if the specified date (year y, month m and day d) is valid.

Example:

QDate::isValid( 2002, 5, 17 );        // TRUE;  May 17th 2002 is OK.
QDate::isValid( 2002, 2, 30 );        // FALSE; Feb 30th does not exist
QDate::isValid( 2004, 2, 29 );        // TRUE; 2004 is a leap year
QDate::isValid( 1202, 6, 6 ); // FALSE; 1202 is pre-Gregorian

Note that a y value in the range 00-99 is interpreted as 1900-1999.

See also: isNull(), setYMD()

Definition at line 477 of file qdatetime.cpp.

 {
     if ( y >= 0 && y <= 99 )
         y += 1900;
     else if ( y < FIRST_YEAR || (y == FIRST_YEAR && (m < 9 ||
                                                     (m == 9 && d < 14))) )
         return FALSE;
     return (d > 0 && m > 0 && m <= 12) &&
            (d <= monthDays[m] || (d == 29 && m == 2 && leapYear(y)));
 }

void QDate::jul2greg	(	uint	jd,
		int &	y,
		int &	m,
		int &	d
	)

staticprotected

Definition at line 528 of file qdatetime.cpp.

 {
     uint x;
     uint j = jd - 1721119;
     y = (j*4 - 1)/146097;
     j = j*4 - 146097*y - 1;
     x = j/4;
     j = (x*4 + 3) / 1461;
     y = 100*y + j;
     x = (x*4) + 3 - 1461*j;
     x = (x + 4)/4;
     m = (5*x - 3)/153;
     x = 5*x - 3 - 153*m;
     d = (x + 5)/5;
     if ( m < 10 ) {
         m += 3;
     } else {
         m -= 9;
         y++;
     }
 }

bool QDate::leapYear ( int y )

static

Returns TRUE if the specified year y is a leap year.

Definition at line 492 of file qdatetime.cpp.

 {
     return (y % 4 == 0 && y % 100 != 0) || (y % 400 == 0);
 }

int QDate::month ( ) const

Returns the month (January=1 .. December=12) of this date.

See also: year(), day()

Definition at line 202 of file qdatetime.cpp.

 {
     int y, m, d;
     jul2greg( jd, y, m, d );
     return m;
 }

QString QDate::monthName ( int month ) const

virtual

Returns the name of the month.

Month 1 == "Jan", month 2 == "Feb" etc.

See also: toString(), dayName()

Definition at line 282 of file qdatetime.cpp.

 {
 #if defined(CHECK_RANGE)
     if ( month < 1 || month > 12 ) {
         qWarning( "QDate::monthName: Parameter out ouf range." );
         month = 1;
     }
 #endif
     // ### Remove the fromLatin1 during localization
     return QString::fromLatin1(monthNames[month-1]);
 }

bool QDate::operator!= ( const QDate & d ) const

inline

Returns TRUE if this date is different from d, or FALSE if they are equal.

Definition at line 79 of file qdatetime.h.

79 { return jd != d.jd; }

QDate::jd

uint jd

Definition: qdatetime.h:95

bool QDate::operator< ( const QDate & d ) const

inline

Returns TRUE if this date is earlier than d, otherwise FALSE.

Definition at line 80 of file qdatetime.h.

80 { return jd < d.jd; }

QDate::jd

uint jd

Definition: qdatetime.h:95

bool QDate::operator<= ( const QDate & d ) const

inline

Returns TRUE if this date is earlier than or equal to d, otherwise FALSE.

Definition at line 81 of file qdatetime.h.

81 { return jd <= d.jd; }

QDate::jd

uint jd

Definition: qdatetime.h:95

bool QDate::operator== ( const QDate & d ) const

inline

Returns TRUE if this date is equal to d, or FALSE if they are different.

Definition at line 78 of file qdatetime.h.

78 { return jd == d.jd; }

QDate::jd

uint jd

Definition: qdatetime.h:95

bool QDate::operator> ( const QDate & d ) const

inline

Returns TRUE if this date is later than d, otherwise FALSE.

Definition at line 82 of file qdatetime.h.

82 { return jd > d.jd; }

QDate::jd

uint jd

Definition: qdatetime.h:95

bool QDate::operator>= ( const QDate & d ) const

inline

Returns TRUE if this date is later than or equal to d, otherwise FALSE.

Definition at line 83 of file qdatetime.h.

83 { return jd >= d.jd; }

QDate::jd

uint jd

Definition: qdatetime.h:95

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

Sets the year y, month m and day d.

y must be in the range 1752-ca. 8000, m must be in the range 1-12, and d must be in the range 1-31. Exception: if y is in the range 0-99, it is interpreted as 1900-1999.

Returns TRUE if the date is valid, otherwise FALSE.

Definition at line 348 of file qdatetime.cpp.

 {
     if ( !isValid(y,m,d) ) {
 #if defined(CHECK_RANGE)
          qWarning( "QDate::setYMD: Invalid date %04d/%02d/%02d", y, m, d );
 #endif
          return FALSE;
     }
     jd = greg2jul( y, m, d );
 #if defined(DEBUG)
     ASSERT( year() == (y > 99 ? y : 1900+y) && month() == m && day() == d );
 #endif
     return TRUE;
 }

QString QDate::toString ( ) const

Returns the date as a string.

The string format is "Sat May 20 1995". This function uses the dayName() and monthName() functions to generate the string.

See also: dayName(), monthName()

Definition at line 324 of file qdatetime.cpp.

 {
     int y, m, d;
     jul2greg( jd, y, m, d );
     QString buf = dayName(dayOfWeek());
     buf += ' ';
     buf += monthName(m);
     QString t;
     t.sprintf( " %d %d", d, y);
     buf += t;
     return buf;
 }

int QDate::year ( ) const

Returns the year (>= 1752) of this date.

See also: month(), day()

Definition at line 189 of file qdatetime.cpp.

 {
     int y, m, d;
     jul2greg( jd, y, m, d );
     return y;
 }

Friends And Related Function Documentation

QDataStream & operator<<	(	QDataStream &	s,
		const QDate &	d
	)

friend

Writes the date to the stream.

See also: Format of the QDataStream operators

Definition at line 1363 of file qdatetime.cpp.

 {
     return s << (Q_UINT32)(d.jd);
 }

QDataStream & operator>>	(	QDataStream &	s,
		QDate &	d
	)

friend

Reads a date from the stream.

See also: Format of the QDataStream operators

Definition at line 1375 of file qdatetime.cpp.

 {
     Q_UINT32 jd;
     s >> jd;
     d.jd = jd;
     return s;
 }

friend class QDateTime

friend

Definition at line 96 of file qdatetime.h.

Member Data Documentation

uint QDate::jd

private

Definition at line 95 of file qdatetime.h.

const char *const QDate::monthNames

staticprivate

Initial value:

= {
    "Jan", "Feb", "Mar", "Apr", "May", "Jun",
    "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" }

Definition at line 93 of file qdatetime.h.

const char *const QDate::weekdayNames

staticprivate

Initial value:

={

"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun" }

Definition at line 94 of file qdatetime.h.

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

doxygen-1.8.11/qtools/qdatetime.h
doxygen-1.8.11/qtools/qdatetime.cpp

Public Member Functions

Static Public Member Functions

Static Protected Member Functions

Private Attributes

Static Private Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

Member Data Documentation