The dates are recorded without time values, as follows: and You can write dates in the same form by using the BDA w. By using the BDN w. This example reads the datetime value by using the BDN w. Here is the output from the SAS log: The BTM w. The BTZ w. You can adjust a time to be the time in another time zone by using a time zone offset. One exception to this rule occurs when a SAS time not a datetime is computed and then formatted with either the BLZ w.
These two formats query the host code to determine the time zone offset. This example reads and writes a Java datetime value and writes the value by using the BDT w. You use the BDX w. The input value is converted to the time for the time zone and formatted using a time zone offset. This example reads the datetime value with an offset — by using the EDZ w. Here is the output from the SAS log: T These two formats query the host code to determine the offset. Each time point begins with P and is followed by the date and time in either basic or extended notation.
Durations can be negative or positive values and can be expressed in these forms: P yyyymmdd T hhmmss. P yyyy-mm-dd T hh:mm:ss.
P yyyy-mm-dd is a span of years, months, and days. P n W specifies the number of weeks. The y , m , and d placeholders must have a value, even if the value is 0. The n placeholder can be 0 or a positive number. The component that contains an n can be omitted. When you use the P n W notation, W must be the only component in the duration. An interval comprises two values that represent the beginning and end of an event, and it is a duration that is anchored to a specific point in time. SAS writes duration, datetime, and interval values from character data by using these formats:.
Time Component. P yyyymmdd T hhmmssfff. Duration - Extended Notation. Duration - Basic and Extended Notation. P n W weeks. Interval - Extended Notation. Datetime - Extended Notation. Writing Partial and Missing Components When any component of a date or time is not provided, it is called a partial value, and the components are considered missing.
You can represent a missing component in a value by using a hyphen - or an x. A single hyphen represents the entire value for a given component. For example, one single hyphen can replace a four-digit year. A single x represents one character for a given component. A missing two-digit month would be written as xx. If the time portion is omitted when a date value is specified, the T must also be omitted. For example, in P2mT4H, the year, day, minutes, and seconds are missing and have been dropped.
Do not confuse missing components with zero values. The durations P3D and P are not the same because a component value of 0 is not the same as a missing component value. Constructs a null time object. For a null time, isNull returns true and isValid returns false. If you need a zero time, use QTime 0, 0.
For the start of a day, see QDate::startOfDay. See also isNull and isValid. Returns a QTime object containing a time ms milliseconds later than the time of this object or earlier if ms is negative. Note that the time will wrap if it passes midnight. See addSecs for an example. Returns a QTime object containing a time s seconds later than the time of this object or earlier if s is negative. Note that the accuracy depends on the accuracy of the underlying operating system; not all systems provide 1-millisecond accuracy.
Furthermore, currentTime only increases within each day; it shall drop by 24 hours each time midnight passes; and, beside this, changes in it may not correspond to elapsed time, if a daylight-saving transition intervenes. Returns a new QTime instance with the time set to the number of msecs since the start of the day, i. If msecs falls outside the valid range an invalid QTime will be returned.
Returns the time represented in the string as a QTime using the format given, or an invalid time if this is not possible. Note that fromString uses a "C" locale encoded string to convert milliseconds to a float value. If the default locale is not "C", this may result in two conversion attempts if the conversion fails for the default locale.
This should be considered an implementation detail. Use QLocale::toTime instead. See also toString and QLocale::toTime. Returns the QTime represented by the string , using the format given, or an invalid time if the string cannot be parsed. All other input characters will be treated as text. Any non-empty sequence of characters enclosed in single quotes will also be treated stripped of the quotes as text and not be interpreted as expressions.
If the format is not satisfied, an invalid QTime is returned. Expressions that do not expect leading zeroes to be given h, m, s and z are greedy. This means that they will use two digits even if this puts them outside the range of accepted values and leaves too few digits for other sections.
For example, the following string could have meant , but the m will grab two digits, resulting in an invalid time:. See also minute , second , and msec. Returns true if the time is null i. So an int32 is sufficient for geological time, but int64 seems overkill to gain astronomical time. In theory every value of JD will be considered valid, although the lowest negative number may be designated the null value rather than using a bool.
Add additional standard date attributes defined in the CLDR such as quarter, months in year, etc, that are useful for calendar systems and date formatting support. The following new api based on CLDR is proposed:. Alternatively NameFormat and NameContext could be merged but this is less future proof, i.
Many apps also need more flexibility in formatting dates. It was suggested to use a regex based fromString method like in QTimeSpan. This can wait for 5. Agreed to remove non-standard format codes, implement as many standard CLDR codes as possible.
Initial implementation may not be most efficient but can be improved later. Must be in 5. The extra Full and Medium formats should be added.
The deprecated ones should be removed, and TextDate investigated to see if it is meaningful anymore. Where the context of the class will determine if it is a date, time or datetime version.
Where a format is inappropriate the default format will be returned. Many locales have an optional Era system for dates, others such as Japan use an era system in its official date formats. Proper localisation support requires this to be added, especially if Calendar Systems are supported.
Qt already provides api for dayOfYear. Qt already provides api for weekNumber. If support for week number systems other than ISO Weeks is added e. US Weeks then the api would be changed to remove the ISO form the name and optionally add the week number system as a parameter. Qt currently only provides standard date math functions for adding years, months or days. Some more convenience functions could be added. The various widgets will need modification to match the new features and api and to resolve old bugs.
Some new widgets may be needed,perhaps based on KDE combo box versions.
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