Stores date and time information. More...

Public Methods
	QDateTime ()

	QDateTime (const QDate &date)

	QDateTime (const QDate &date, const QTime &time, std::optional< QTimeZone > timeZone=std::nullopt)

	QDateTime (const QDateTime &other)

	QDateTime (QDateTime &&other)

	~QDateTime ()

QDateTime	addDays (qint64 days) const

QDateTime	addDuration (std::chrono::milliseconds msecs) const

QDateTime	addMonths (qint64 months) const

QDateTime	addMSecs (qint64 msecs) const

QDateTime	addSecs (qint64 seconds) const

QDateTime	addYears (qint64 years) const

QDate	date () const

qint64	daysTo (const QDateTime &value) const

bool	isDaylightTime () const

bool	isNull () const

bool	isValid () const

qint64	msecsTo (const QDateTime &value) const

int	offsetFromUtc () const

bool	operator!= (const QDateTime &value) const

bool	operator< (const QDateTime &value) const

bool	operator<= (const QDateTime &value) const

QDateTime &	operator= (const QDateTime &other)

QDateTime &	operator= (QDateTime &&other)

bool	operator== (const QDateTime &value) const

bool	operator> (const QDateTime &value) const

bool	operator>= (const QDateTime &value) const

qint64	secsTo (const QDateTime &value) const

void	setDate (const QDate &date)

void	setMSecsSinceEpoch (qint64 msecs)

void	setSecsSinceEpoch (qint64 seconds)

void	setTime (const QTime &time)

void	setTime_t (quint64 seconds)

void	setTimeZone (const QTimeZone &toZone)

void	swap (QDateTime &other)

QTime	time () const

QTimeZone	timeRepresentation () const

QTimeZone	timeZone () const

QString	timeZoneAbbreviation () const

CFDateRef	toCFDate () const

QDateTime	toLocalTime () const

qint64	toMSecsSinceEpoch () const

NSDate *	toNSDate () const

QDateTime	toOffsetFromUtc (qint64 offsetSeconds) const

qint64	toSecsSinceEpoch () const

std::chrono::time_point< std::chrono::system_clock, std::chrono::milliseconds >	toStdSysMilliseconds () const

std::chrono::time_point< std::chrono::system_clock, std::chrono::seconds >	toStdSysSeconds () const

QString	toString (const QString &format) const

QString	toString (Qt::DateFormat format=Qt::TextDate) const

quint64	toTime_t () const

QDateTime	toTimeZone (const QTimeZone &timeZone) const

QDateTime	toUTC () const

Static Public Methods
static QDateTime	currentDateTime (const QTimeZone &zone=QDate::default_tz ())

static QDateTime	currentDateTimeUtc ()

static qint64	currentMSecsSinceEpoch ()

static qint64	currentSecsSinceEpoch ()

static QDateTime	fromCFDate (CFDateRef date)

static QDateTime	fromMSecsSinceEpoch (qint64 msecs, const QTimeZone &timeZone=QDate::default_tz ())

static QDateTime	fromNSDate (const NSDate *date)

static QDateTime	fromSecsSinceEpoch (qint64 seconds, const QTimeZone &timeZone=QDate::default_tz ())

static QDateTime	fromStdLocalTime (const std::chrono::local_time< std::chrono::milliseconds > &msecs)

static QDateTime	fromString (const QString &str, const QString &format)

static QDateTime	fromString (const QString &str, Qt::DateFormat format=Qt::TextDate)

static QDateTime	fromTime_t (qint64 seconds, const QTimeZone &timeZone=QDate::default_tz ())

Friends
QDataStream &	operator<< (QDataStream &stream, const QDateTime &dateTime)

QDataStream &	operator>> (QDataStream &stream, QDateTime &dateTime)

Detailed Description

The QDateTime class stores date and time information. The Julian calendar is used for any date prior to October 15 1582. The Gregorian calendar is used for dates after 15 October 1582. This class retrieves the current date and time from the operating system internal clock. Many of the methods in this class are used to calculate a new date or time based on a given offset or to compare two existing dates or times.

QDateTime does not account for leap seconds.

A QDateTime is typically created by specifying a QDate and a QTime or using the static method currentDateTime() which returns a new QDateTime based on the system clock. The date() and time() methods return a QDate and QTime. Calling toString() returns the date and time in a text format.

The date and time for a given QDateTime can be modified by calling setDate() and setTime(). The fromString() method returns a new QDateTime based on a quoted string and a date/time format.

There are a full set of operators to compare two QDateTime values where a smaller date/time one means earlier and a larger date/time is later.

Gregorian and Julian Calendars

The switch from the Julian calendar to the Gregorian calendar happened between October 4 1582 to October 15 1582. This 10 day gap is part of Roman history and the actually skipped these days to adjust to the new calendar. Other regions of the world made the calendar transition at different times, although many areas moved within a year. Notable exceptions are the British Empire which changed over in 1752 and Greece with moved to the Gregorian calendar in 1923.

CopperSpice follows the common practice of using the calendar corresponding to the Roman locale. QDateTime uses the Julian calendar for dates prior to October 4 1582 and the Gregorian calendar starting on October 15 1582. All dates within the gap are invalid.

If you use QDateTime for a calendar date in this range, the day after 4 October 1582 will be 15 October 1582.

Year 0

There is no year 0 and attempting to construct a date for that year results in an invalid QDateTime.

The year -1 refers to the year "1 before Christ" or BCE which stands for "before common era". The day before January 1 0001 is December 31 0001 BCE. The notation CE stands for "common era" and refers to dates "after Christ".

Before Common Era

lifetime of Alexander the Great
construction of the Egyptian Pyramids
abacus invented in Sumer and Babylonia

Common Era

development of computer software
invention of the moterized vehicles
birthday of anyone reading this documentation

Range of Valid Dates

The QDate class is implemented using a qint64 which stores the number of days since November 24 4714 BCE in the Gregorian calendar. QDateTime is also implemented using a qint64 which stores the number of milliseconds since Jan 1 1970 at midnight UTC.

For most use cases QDate and QDateTime will store the same date value. You should use QDate to prevent an overflow when the calendar date might be extremely far in the past or the future.

Use of System Timezone

QDateTime uses the operating system time zone information to determine the offset of local time from UTC. If the system is not configured correctly QDateTime may return incorrect values.

QDateTime::currentDateTime() returns a QDateTime expressed as local time. Use the method toUTC() to convert local time to UTC time. Operations such as addSecs() and secsTo() are aware of daylight saving time (DST).

Daylight Saving Time (DST)

QDateTime uses the operating system time zone database to determine when Daylight Saving Time starts and ends for a given locale.

See also: QDate, QDateTimeEdit, QTime, QTimeZone

Constructor & Destructor Documentation

QDateTime::QDateTime ( )

Constructs an invalid QDateTime.

See also: isValid()

QDateTime::QDateTime ( const QDate & date )

explicit

Constructs a QDateTime with the given date and a valid QTime of 00:00:00.000.

QDateTime::QDateTime	(	const QDate &	date,
		const QTime &	time,
		std::optional< QTimeZone >	timeZone = `std::nullopt`
	)

Constructs a new QDateTime with the given date and time using the specified timeZone. If the date is valid and time is not valid, the time will automatically be set to midnight. If the specified timeZone is invalid the QDateTime will be invalid.

QDateTime::QDateTime ( const QDateTime & other )

Copy constructs a new QDateTime from other.

QDateTime::QDateTime ( QDateTime && other )

Move constructs a new QDateTime from other.

QDateTime::~QDateTime ( )

Destroys this QDateTime.

Method Documentation

QDateTime QDateTime::addDays ( qint64 days ) const

nodiscard

Adds the number of days to the current QDateTime and returns the result. If days is negative the value for days is subtracted from this QDateTime.

See also: addMonths(), addYears(), addSecs(), daysTo()

QDateTime QDateTime::addDuration ( std::chrono::milliseconds msecs ) const

Adds the number of msecs to the current QDateTime and returns the result. If msecs is negative the value for msecs is subtracted from this QDateTime.

See also: addMSecs(), msecsTo()

QDateTime QDateTime::addMonths ( qint64 months ) const

nodiscard

Adds the given number of months to the current QDateTime and returns the result. If months is negative the value for months is subtracted from this QDateTime.

See also: addDays(), addSecs(), addYears(), daysTo()

QDateTime QDateTime::addMSecs ( qint64 msecs ) const

nodiscard

Adds the number of msecs to the current QDateTime and returns the result. If msecs is negative the value for msecs is subtracted from this QDateTime.

See also: addSecs(), msecsTo()

QDateTime QDateTime::addSecs ( qint64 seconds ) const

nodiscard

Adds the given number of seconds to the current QDateTime and returns the result. If seconds is negative the value for seconds is subtracted from this QDateTime.

See also: addDays(), addMonths(), addMSecs(), addYears(), secsTo()

QDateTime QDateTime::addYears ( qint64 years ) const

nodiscard

Adds the given number of years to the current QDateTime and returns the result. If years is negative the value for years is subtracted from this QDateTime.

See also: addDays(), addMonths(), addSecs(), daysTo()

QDateTime QDateTime::currentDateTime ( const QTimeZone & zone = QDate::default_tz() )

static

Returns the current QDateTime based on the system clock. If no value for zone is passed the local time zone will be used.

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

QDateTime QDateTime::currentDateTimeUtc ( )

static

Returns a QDateTime based on the system clock, in UTC.

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

qint64 QDateTime::currentMSecsSinceEpoch ( )

static

Returns the number of milliseconds since Jan 1 1970 at midnight UTC.

See also: currentDateTime(), currentDateTimeUtc(), toTime_t()

qint64 QDateTime::currentSecsSinceEpoch ( )

static

Returns the number of seconds since Jan 1 1970 at midnight UTC.

See also: currentDateTime(), currentDateTimeUtc(), toTime_t()

QDate QDateTime::date ( ) const

Returns the date part of the current QDateTime.

See also: setDate(), time()

qint64 QDateTime::daysTo ( const QDateTime & value ) const

Returns the number of days between the current QDateTime and the given value. If the new QDateTime is earlier than the original QDateTime, the value returned is negative.

See also: addDays(), secsTo(), msecsTo()

QDateTime QDateTime::fromCFDate ( CFDateRef date )

static

Constructs a new QDateTime containing a copy of the CFDate date.

Note: This method is only available on Mac OS X.

See also: toCFDate()

QDateTime QDateTime::fromMSecsSinceEpoch	(	qint64	msecs,
		const QTimeZone &	timeZone = `QDate::default_tz()`
	)

static

Returns a QDateTime where the date and time correspond to the given number of msecs since Jan 1 1970 at midnight UTC, with the specified timeZone.

See also: fromTime_t()

QDateTime QDateTime::fromNSDate ( const NSDate * date )

static

Constructs a new QDateTime containing a copy of the NSDate date.

Note: This method is only available on Mac OS X.

See also: toNSDate()

QDateTime QDateTime::fromSecsSinceEpoch	(	qint64	seconds,
		const QTimeZone &	timeZone = `QDate::default_tz()`
	)

static

Returns a QDateTime containing the date and time equal to the number of seconds after Jan 1 1970 at midnight UTC. If a valid timeZone is specified the returned QDateTime will be adjusted accordingly. If no timeZone is passed the local system time zone will be used.

There are values for seconds which will result in a QDateTime that is invalid. For these values the behavior of this method is undefined.

See also: fromMSecsSinceEpoch(), setSecsSinceEpoch(), toSecsSinceEpoch()

QDateTime QDateTime::fromStdLocalTime ( const std::chrono::local_time< std::chrono::milliseconds > & msecs )

inlinestatic

Returns a QDateTime where the date and time is calculated by adding msecs to Jan 1 1970 at midnight local time.

Note: This method is only available if your compiler supports the C++20 features of std::chrono.

QDateTime QDateTime::fromString	(	const QString &	str,
		const QString &	format
	)

static

Returns the QDateTime represented by str using the given format. Returns an invalid QDateTime if str does not match the specified format.

The day and month names must be given in the user locale. You can only use the English names if the current locale is English.

These expressions may be used for the date part of the format string.

Expression	Output
d	the day as number without a leading zero (1 to 31)
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. 'Monday' to 'Sunday'). 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 (00-99)
yyyy	the year as four digit number

These expressions may be used for the time part of the format string.

Expression	Output
h	hour without a leading zero (0 to 23 or 1 to 12 if AM/PM display)
hh	hour with a leading zero (00 to 23 or 01 to 12 if AM/PM display)
H	hour without a leading zero (0 to 23, even with AM/PM display)
HH	hour with a leading zero (00 to 23, even with AM/PM display)
m	minute without a leading zero (0 to 59)
mm	minute with a leading zero (00 to 59)
s	second without a leading zero (0 to 59)
ss	second with a leading zero (00 to 59)
z	milliseconds without leading zeroes (0 to 999)
zzz	milliseconds with leading zeroes (000 to 999)
AP or A	interpret as an AM/PM time, AP must be either "AM" or "PM".
ap or a	Interpret as an AM/PM time, ap must be either "am" or "pm".

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

QTime time1 = QTime::fromString("131", "HHh");
// time1 is 13:00:00
 
QTime time2 = QTime::fromString("1apA", "1amAM");
// time2 is 01:00:00
 
QDateTime dateTime = QDateTime::fromString("M1d1y9800:01:02", "'M'M'd'd'y'yyhh:mm:ss");
// dateTime is 1 January 1998 00:01:02

If the format is not satisfied an invalid QDateTime is returned.

The expressions which do not expect leading zeroes (d, M) will be greedy. This means 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 does not mean January 30 because the M will grab two digits, resulting in an invalid date.

QDateTime dateTime = QDateTime::fromString("130", "Mm"); // invalid

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

Field	Default value
Year	1900
Month	1 (January)
Day	1
Hour	0
Minute	0
Second	0

QDateTime dateTime = QDateTime::fromString("1.30.1", "M.d.s"); // dateTime is January 30 in 1900 at 00:00:01.

See also: QDate::fromString(), QTime::fromString(), QDate::toString()

QDateTime QDateTime::fromString	(	const QString &	str,
		Qt::DateFormat	format = `Qt::TextDate`
	)

static

Returns the QDateTime represented by str using the given format. Returns an invalid QDateTime if str does not match the specified format.

QDateTime QDateTime::fromTime_t	(	qint64	seconds,
		const QTimeZone &	timeZone = `QDate::default_tz()`
	)

static

Returns a QDateTime where the date and time are the number of seconds since Jan 1 1970 at midnight UTC with the given timeZone.

See also: toTime_t(), setTime_t()

bool QDateTime::isDaylightTime ( ) const

Returns true if this QDateTime falls in the region of Daylight Saving Time.

bool QDateTime::isNull ( ) const

Returns true if both the date and the time are null, otherwise returns false. A null QDateTime is invalid.

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

bool QDateTime::isValid ( ) const

Returns true if both the date and the time are valid, otherwise returns false.

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

qint64 QDateTime::msecsTo ( const QDateTime & value ) const

Returns the number of milliseconds between the current QDateTime and the given value. If the new QDateTime is earlier than the original QDateTime, the value returned is negative.

This method will convert both QDateTime values to UTC. This will ensure the result is correct if one of the values uses daylight saving time (DST) and the other does not.

See also: addMSecs(), daysTo(), QTime::msecsTo()

int QDateTime::offsetFromUtc ( ) const

Returns the number of seconds between the time zone for this QDateTime and the UTC clock.

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

inline

Returns true if this QDateTime is different from the given value, otherwise returns false. Two datetimes are different if the date, the time, or the time zone components are different.

See also: operator==()

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

Returns true if this QDateTime is earlier than the given value, otherwise returns false.

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

inline

Returns true if this QDateTime is earlier than or equal to the given value, otherwise returns false.

QDateTime & QDateTime::operator= ( const QDateTime & other )

Copy assigns from other and returns a reference to this object.

QDateTime & QDateTime::operator= ( QDateTime && other )

inline

Move assigns from other and returns a reference to this object.

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

Returns true if this QDateTime is equal to the given value, otherwise returns false.

See also: operator!=()

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

inline

Returns true if this QDateTime is later than the given value, otherwise returns false.

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

inline

Returns true if this QDateTime is later than or equal to the given value, otherwise returns false.

qint64 QDateTime::secsTo ( const QDateTime & value ) const

Returns the number of seconds between the current QDateTime and the given value. If the new QDateTime is earlier than the original QDateTime, the value returned is negative.

This method will convert both QDateTime values to UTC. This will ensure the result is correct if one of the values uses daylight saving time (DST) and the other does not.

QDateTime now = QDateTime::currentDateTime();
QDateTime xmas(QDate(now.date().year(), 12, 25), QTime(0, 0));
 
qDebug("There are %d seconds to Christmas", now.secsTo(xmas));

See also: addSecs(), daysTo(), QTime::secsTo()

void QDateTime::setDate ( const QDate & date )

Sets the date part of this QDateTime to date. If no time is set, the time is set to midnight.

See also: date(), setTime()

void QDateTime::setMSecsSinceEpoch ( qint64 msecs )

Sets the date and time for this QDateTime which corresponds to the given number of msecs since Jan 1 1970 at midnight UTC.

There are values for msecs which will result in a QDateTime that is invalid. For these values the behavior of this method is undefined.

See also: toMSecsSinceEpoch(), setTime_t()

void QDateTime::setSecsSinceEpoch ( qint64 seconds )

Sets the date and time for this QDateTime which corresponds to the given number of seconds since Jan 1 1970 at midnight UTC.

See also: fromSecsSinceEpoch(), setMSecsSinceEpoch(), toSecsSinceEpoch()

void QDateTime::setTime ( const QTime & time )

Sets the time part of this QDateTime to time.

See also: time(), setDate()

void QDateTime::setTime_t ( quint64 seconds )

Sets the date and time which correspond to the given number of seconds since Jan 1 1970 at midnight UTC.

See also: toTime_t()

void QDateTime::setTimeZone ( const QTimeZone & toZone )

Sets the time zone for this QDateTime to toZone. If the specified time zone is invalid then the QDateTime will be invalid.

See also: timeZone()

void QDateTime::swap ( QDateTime & other )

inline

Swaps other with this QDateTime.

QTime QDateTime::time ( ) const

Returns the time part of this QDateTime.

See also: setTime(), date()

QTimeZone QDateTime::timeRepresentation ( ) const

Returns the time zone for the current QDateTime. Equivalent to calling QDateTime::timeZone().

See also: setTimeZone()

QTimeZone QDateTime::timeZone ( ) const

Returns the time zone for the current QDateTime. Equivalent to calling QDateTime::timeRepresentation().

See also: setTimeZone()

QString QDateTime::timeZoneAbbreviation ( ) const

Returns the Time Zone Abbreviation for this QDateTime. The abbreviation is not guaranteed to be unique to a particular time zone and should not be used in place of the ID or display name.

An example abbreviation for Chicago or New Orleans would be CST or CDT for "central standard time" and "central daylight time". In Amsterdam or Berlin the abbreviation will be CET or CEST for "central european time" and "central european summer time".

See also: QTimeZone::abbreviation()

CFDateRef QDateTime::toCFDate ( ) const

Creates a CFDate from this QDateTime. The caller owns the CFDate object and is responsible for releasing it.

Note: This method is only available on Mac OS X.

See also: fromCFDate()

QDateTime QDateTime::toLocalTime ( ) const

Returns the current QDateTime converted to the local time zone.

qint64 QDateTime::toMSecsSinceEpoch ( ) const

Returns this QDateTime as the number of milliseconds since Jan 1 1970 at midnight UTC. This method returns a unique value for all valid dates. If the QDateTime is invalid the result is undefined.

See also: toTime_t(), setMSecsSinceEpoch()

NSDate * QDateTime::toNSDate ( ) const

Creates an NSDate from a QDateTime. The NSDate object is autoreleased.

Note: This method is only available on Mac OS X.

See also: fromNSDate()

QDateTime QDateTime::toOffsetFromUtc ( qint64 offsetSeconds ) const

Returns a copy of the current QDateTime which is converted to a time zone corresponding to the offsetSeconds relative to UTC. If the offsetSeconds equals 0 then the date time will be in UTC.

See also: offsetFromUtc()

qint64 QDateTime::toSecsSinceEpoch ( ) const

Converts this QDateTime to the number of seconds since Jan 1 1970 at midnight UTC. For all valid dates this method returns a unique value.

On systems which do not support time zones this method will behave as if local time were UTC. The behavior for this method is undefined if the QDateTime is not valid.

See also: toMSecsSinceEpoch(), fromSecsSinceEpoch(), setSecsSinceEpoch()

std::chrono::time_point< std::chrono::system_clock, std::chrono::milliseconds > QDateTime::toStdSysMilliseconds ( ) const

inline

Converts this QDateTime to a value in milliseconds using the std::chrono::system_clock. The value is the duration from Jan 1 1970 at midnight UTC to this QDateTime.

See also: fromStdLocalTime(), toMSecsSinceEpoch()

std::chrono::time_point< std::chrono::system_clock, std::chrono::seconds > QDateTime::toStdSysSeconds ( ) const

inline

Converts this QDateTime to a value in seconds using the std::chrono::system_clock. The value is the duration from Jan 1 1970 at midnight UTC to this QDateTime.

See also: fromStdLocalTime(), toSecsSinceEpoch()

QString QDateTime::toString ( const QString & format ) const

Returns this QDateTime as a string. The format parameter determines the format of the result string. If the QDateTime is invalid an empty string will be returned.

These expressions are used for the date.

Expression	Output
d	the day as number without a leading zero (1 to 31)
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. 'Monday' to 'Sunday'). 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 (00-99)
yyyy	the year as four digit number

These expressions are used for the time.

Expression	Output
h	hour without a leading zero (0 to 23 or 1 to 12 if AM/PM display)
hh	hour with a leading zero (00 to 23 or 01 to 12 if AM/PM display)
m	minute without a leading zero (0 to 59)
mm	minute with a leading zero (00 to 59)
s	second without a leading zero (0 to 59)
ss	second with a leading zero (00 to 59)
z	milliseconds without leading zeroes (0 to 999)
zzz	milliseconds with leading zeroes (000 to 999)
AP	AM/PM display. AP will be replaced by either "AM" or "PM".
ap	am/pm display. ap will be replaced by either "am" or "pm".

All other input characters will be ignored. Any sequence of characters which are enclosed in single quotes will be treated as text and not used as an expression. Two consecutive singlequotes are replaced by a single quote in the output.

The following examples assume the QDateTime is "21 May 2001 14:13:09".

Format	Result
dd.MM.yyyy	21.05.2001
ddd MMMM d yy	Tue May 21 01
hh:mm:ss.zzz	14:13:09.042
h:m:s ap	2:13:9 pm

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

QString QDateTime::toString ( Qt::DateFormat format = Qt::TextDate ) const

Returns this QDateTime as a string in the given format. If this QDateTime is invalid an empty string will be returned.

Qt::TextDate formats the string using the default as specified in the Qt::DateFormat enum. An example of this formatting is "Tue May 20 03:40:13 2008".

Qt::ISODate uses the ISO 8601 extended specification of yyyy-MM-ddThh:mm:ss[Z|[+|-]hh:mm]. This format is only valid for years in the range 0 to 9999.

Qt::RFC2822Date uses the specification d MMM yyyy hh:mm:ss [+|-]hh:mm.

Qt::SystemLocaleShortDate or Qt::SystemLocaleLongDate will format the string based on the locale settings of the current system.

Qt::DefaultLocaleShortDate or Qt::DefaultLocaleLongDate formats the string depends on the default application locale. The default locale is set by calling QLocale::setDefault(). If no default locale has been set the system locale will be used.

See also: fromString(), Qt::DateFormat

quint64 QDateTime::toTime_t ( ) const

Converts this QDateTime to the number of seconds which have elapsed since Jan 1, 1970 at midnight UTC.

See also: toMSecsSinceEpoch(), setTime_t()

QDateTime QDateTime::toTimeZone ( const QTimeZone & timeZone ) const

Returns a copy of this QDateTime converted to the given timeZone.

See also: timeZone()

QDateTime QDateTime::toUTC ( ) const

Converts the current QDateTime to UTC.

Refer to UTC Defined for additional information.

Friends And Related Function Documentation

QDataStream & operator<<	(	QDataStream &	stream,
		const QDateTime &	dateTime
	)

friend

Writes the given dateTime to the stream. Returns a reference to the stream.

Refer to Serializing Data Types for additional information.

QDataStream & operator>>	(	QDataStream &	stream,
		QDateTime &	dateTime
	)

friend

Reads from the stream into the given dateTime. Returns a reference to the stream.

Refer to Serializing Data Types for additional information.

Public Methods

Static Public Methods

Friends

Detailed Description

Gregorian and Julian Calendars

Year 0

Range of Valid Dates

Use of System Timezone

Daylight Saving Time (DST)

Constructor & Destructor Documentation

Method Documentation

Friends And Related Function Documentation