QDate

NAME

SYNOPSIS

#include <qdatetime.h>

Public Members

Static Public Members

RELATED FUNCTION DOCUMENTATION

DESCRIPTION

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 dates, e.g. by adding a number of days or months or years.

A QDate object is typically created either by giving the year, month and day numbers explicitly, or by using the static function currentDate(), which creates a QDate object containing the system clock's date. An explicit date can also be set using setYMD(). 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 leapYear() function indicates whether this date is in a leap year.

Note that QDate should not be used for date calculations for dates prior to the introduction of the Gregorian calendar. This calendar was adopted by England from the 14^{<small>th</small>} September 1752 (hence this is the earliest valid QDate), and subsequently by most other Western countries, until 1923.

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

See also QTime, QDateTime, QDateEdit, QDateTimeEdit, and Time and Date.  

MEMBER FUNCTION DOCUMENTATION

QDate::QDate ()

See also isNull() and isValid().  

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

y must be in the range 1752..8000, m must be in the range 1..12, and d must be in the range 1..31.

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

See also isValid().  

QDate QDate::addDays ( int ndays ) const

See also addMonths(), addYears(), and daysTo().  

QDate QDate::addMonths ( int nmonths ) const

See also addDays() and addYears().  

QDate QDate::addYears ( int nyears ) const

See also addDays() and addMonths().  

QDate QDate::currentDate ( Qt::TimeSpec ts ) [static]

See also QTime::currentTime(), QDateTime::currentDateTime(), and Qt::TimeSpec.

Example: dclock/dclock.cpp.  

QDate QDate::currentDate () [static]

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

See also QTime::currentTime() and QDateTime::currentDateTime().  

int QDate::day () const

See also year(), month(), and dayOfWeek().

Example: dclock/dclock.cpp.  

QString QDate::dayName ( int weekday ) [static]

Use shortDayName() instead.  

int QDate::dayOfWeek () const

See also day() and dayOfYear().  

int QDate::dayOfYear () const

See also day() and dayOfWeek().  

int QDate::daysInMonth () const

See also day() and daysInYear().  

int QDate::daysInYear () const

See also day() and daysInMonth().  

int QDate::daysTo ( const QDate & d ) const

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().  

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

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.  

bool QDate::isNull () const

See also isValid().  

bool QDate::isValid () const

See also isNull().  

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; otherwise returns FALSE.

Example:

    QDate::isValid( 2002, 5, 17 );  // TRUE   May 17th 2002 is valid


    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

Warning: A y value in the range 00..99 is interpreted as 1900..1999.

See also isNull() and setYMD().  

bool QDate::leapYear ( int y ) [static]

QString QDate::longDayName ( int weekday ) [static]

1 = "Monday", 2 = "Tuesday", ... 7 = "Sunday"

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

See also toString(), shortDayName(), shortMonthName(), and longMonthName().  

QString QDate::longMonthName ( int month ) [static]

1 = "January", 2 = "February", ... 12 = "December"

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

See also toString(), shortMonthName(), shortDayName(), and longDayName().  

int QDate::month () const

See also year() and day().

Example: dclock/dclock.cpp.  

QString QDate::monthName ( int month ) [static]

Use shortMonthName() instead.  

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

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

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

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