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The QDate class provides date functions. More...
#include <qdatetime.h>
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 isNull() and isValid().
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().
See also daysTo().
See also QTime::currentTime() and QDateTime::currentDateTime().
Example: dclock/dclock.cpp.
See also year(), month() and dayOfWeek().
Example: dclock/dclock.cpp.
Weekday 1 == "Mon", day 2 == "Tue" etc.
See also toString() and monthName().
See also day() and dayOfYear().
See also day() and dayOfWeek().
See also day() and daysInYear().
See also day() and daysInMonth().
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().
Returns TRUE if the date is null. A null date is invalid.
See also isValid().
See also isNull().
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() and setYMD().
Example: dclock/dclock.cpp.
Month 1 == "Jan", month 2 == "Feb" etc.
See also toString() and dayName().
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.
If f is Qt::TextDate, the string format is "Sat May 20 1995" (using the dayName() and monthName() functions to generate the string).
If f is Qt::ISODate, the string format corresponds to the ISO 8601 specification for representations of dates, which is 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.
See also dayName() and monthName().
See also Format of the QDataStream operators.
See also Format of the QDataStream operators.
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