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QDateTime Class Reference

The QDateTime class provides date and time functions. More...

#include <qdatetime.h>

Public Member Functions

 QDateTime ()
 
 QDateTime (const QDate &)
 
 QDateTime (const QDate &, const QTime &)
 
bool isNull () const
 
bool isValid () const
 
QDate date () const
 
QTime time () const
 
void setDate (const QDate &date)
 
void setTime (const QTime &time)
 
void setTime_t (uint secsSince1Jan1970UTC)
 
void setTimeUtc_t (uint secsSince1Jan1970UTC)
 
QString toString () const
 
QDateTime addDays (int days) const
 
QDateTime addSecs (int secs) const
 
int daysTo (const QDateTime &) const
 
int secsTo (const QDateTime &) const
 
bool operator== (const QDateTime &dt) const
 
bool operator!= (const QDateTime &dt) const
 
bool operator< (const QDateTime &dt) const
 
bool operator<= (const QDateTime &dt) const
 
bool operator> (const QDateTime &dt) const
 
bool operator>= (const QDateTime &dt) const
 

Static Public Member Functions

static QDateTime currentDateTime ()
 

Friends

Q_EXPORT QDataStream & operator<< (QDataStream &, const QDateTime &)
 
Q_EXPORT QDataStream & operator>> (QDataStream &, QDateTime &)
 

Detailed Description

The QDateTime class provides date and time functions.

A QDateTime object contains a calendar date and a clock time (a "datetime"). It is a combination of the QDate and QTime classes. It can read the current datetime from the system clock. It provides functions for comparing datetimes and for manipulating a datetime by adding a number of seconds or days.

A QDateTime object is typically created either by giving a date and time explicitly, or by using the static function currentTime(), which makes a QDateTime object which contains the system's clock time.

The date() and time() functions provide access to the date and time parts of the datetime. The same information is provided in textual format by the toString() function.

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

The datetime a given number of days or seconds later than a given datetime can be found using the addDays() and addSecs() functions. Correspondingly, the number of days or seconds between two times can be found using the daysTo() or secsTo() functions.

A datetime can also be set using the setTime_t() function, which takes a POSIX-standard "number of seconds since 00:00:00 on January 1, 1970" value.

The limitations regarding range and resolution mentioned in the QDate and QTime documentation apply for QDateTime also.

See also
QDate, QTime

Constructor & Destructor Documentation

§ QDateTime() [1/3]

QDateTime::QDateTime ( )
inline

Constructs a null datetime (i.e. null date and null time). A null datetime is invalid, since the date is invalid.

See also
isValid()

§ QDateTime() [2/3]

QDateTime::QDateTime ( const QDate &  date)

Constructs a datetime with date date and null time (00:00:00.000).

§ QDateTime() [3/3]

QDateTime::QDateTime ( const QDate &  date,
const QTime &  time 
)

Constructs a datetime with date date and time time.

Member Function Documentation

§ addDays()

QDateTime QDateTime::addDays ( int  ndays) const

Returns a QDateTime object containing a datetime ndays days later than the datetime of this object (or earlier if ndays is negative).

See also
daysTo(), addSecs()

§ addSecs()

QDateTime QDateTime::addSecs ( int  nsecs) const

Returns a QDateTime object containing a datetime nsecs seconds later than the datetime of this object (or earlier if nsecs is negative).

See also
secsTo(), addDays()

§ currentDateTime()

QDateTime QDateTime::currentDateTime ( )
static

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

See also
QDate::currentDate(), QTime::currentTime()

§ date()

QDate QDateTime::date ( ) const
inline

Returns the date part of this datetime.

See also
setDate(), time()

§ daysTo()

int QDateTime::daysTo ( const QDateTime &  dt) const

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

See also
addDays(), secsTo()

§ isNull()

bool QDateTime::isNull ( ) const
inline

Returns TRUE if both the date and the time are null. A null date is invalid.

See also
QDate::isNull(), QTime::isNull()

§ isValid()

bool QDateTime::isValid ( ) const
inline

Returns TRUE if both the date and the time are valid.

See also
QDate::isValid(), QTime::isValid()

§ operator!=()

bool QDateTime::operator!= ( const QDateTime &  dt) const

Returns TRUE if this datetime is different from dt, or FALSE if they are equal.

See also
operator==()

§ operator<()

bool QDateTime::operator< ( const QDateTime &  dt) const

Returns TRUE if this datetime is earlier than dt, otherwise FALSE.

§ operator<=()

bool QDateTime::operator<= ( const QDateTime &  dt) const

Returns TRUE if this datetime is earlier than or equal to dt, otherwise FALSE.

§ operator==()

bool QDateTime::operator== ( const QDateTime &  dt) const

Returns TRUE if this datetime is equal to dt, or FALSE if they are different.

See also
operator!=()

§ operator>()

bool QDateTime::operator> ( const QDateTime &  dt) const

Returns TRUE if this datetime is later than dt, otherwise FALSE.

§ operator>=()

bool QDateTime::operator>= ( const QDateTime &  dt) const

Returns TRUE if this datetime is later than or equal to dt, otherwise FALSE.

§ secsTo()

int QDateTime::secsTo ( const QDateTime &  dt) const

Returns the number of seconds from this datetime to dt (which is negative if dt is earlier than this datetime).

Example:

QDateTime dt = QDateTime::currentDateTime();
QDateTime x( QDate(dt.year(),12,24), QTime(17,00) );
qDebug( "There are %d seconds to Christmas", dt.secsTo(x) );
See also
addSecs(), daysTo(), QTime::secsTo()

§ setDate()

void QDateTime::setDate ( const QDate &  date)
inline

Sets the date part of this datetime.

See also
date(), setTime()

§ setTime()

void QDateTime::setTime ( const QTime &  time)
inline

Sets the time part of this datetime.

See also
time(), setDate()

§ setTime_t()

void QDateTime::setTime_t ( uint  secsSince1Jan1970UTC)

Sets the local date and time given the number of seconds that have passed since 00:00:00 on January 1, 1970, Coordinated Universal Time (UTC). On systems that do not support timezones this function will behave as if local time were UTC.

Note that Microsoft Windows supports only a limited range of values for secsSince1Jan1970UTC.

§ setTimeUtc_t()

void QDateTime::setTimeUtc_t ( uint  secsSince1Jan1970UTC)

Sets the UTC date and time given the number of seconds that have passed since 00:00:00 on January 1, 1970, Coordinated Universal Time (UTC).

Note that Microsoft Windows supports only a limited range of values for secsSince1Jan1970UTC.

§ time()

QTime QDateTime::time ( ) const
inline

Returns the time part of this datetime.

See also
setTime(), date()

§ toString()

QString QDateTime::toString ( ) const

Returns the datetime as a string.

The string format is "Sat May 20 03:40:13 1998".

This function uses QDate::dayName(), QDate::monthName(), and QTime::toString() to generate the string.

Friends And Related Function Documentation

§ operator<<

QDataStream & operator<< ( QDataStream &  s,
const QDateTime &  dt 
)
friend

Writes a datetime to the stream.

See also
Format of the QDataStream operators

§ operator>>

QDataStream & operator>> ( QDataStream &  s,
QDateTime &  dt 
)
friend

Reads a datetime from the stream.

See also
Format of the QDataStream operators
The documentation for this class was generated from the following files:
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