Public Types¶

enum Week0Type { FirstThursday, FirstDay }
enum IntervalType { Millisecond, Second, Minute, Hour, Day, Week, Month, Year }
enum { JulianDayForEpoch = 2440588 }

Static Public Member Functions¶

static QDate minDate ()
static QDate maxDate ()
static QDateTime toDateTime (double value, Qt::TimeSpec=Qt::UTC)
static double toDouble (const QDateTime &)
static QDateTime ceil (const QDateTime &, IntervalType)
static QDateTime floor (const QDateTime &, IntervalType)
static QDate dateOfWeek0 (int year, Week0Type)
Date of the first day of the first week for a year. static int weekNumber (const QDate &, Week0Type)
static int utcOffset (const QDateTime &)
static QString toString (const QDateTime &, const QString &format, Week0Type)

anonymous enum¶

Enumerator

JulianDayForEpoch

The Julian day of 'The Epoch'.

enum QwtDate::IntervalType¶

Classification of an time interval

Time intervals needs to be classified to decide how to align and divide it.

Enumerator

Millisecond

The interval is related to milliseconds.

Second

The interval is related to seconds.

Minute

The interval is related to minutes.

Hour

The interval is related to hours.

Day

The interval is related to days.

Week

The interval is related to weeks.

Month

The interval is related to months.

Year

The interval is related to years.

enum QwtDate::Week0Type¶

How to identify the first week of year differs between countries.

Enumerator

FirstThursday

According to ISO 8601 the first week of a year is defined as 'the week with the year's first Thursday in it'.

FirstThursday corresponds to the numbering that is implemented in QDate::weekNumber().

FirstDay

In the U.S. this definition is more common than FirstThursday.

QDateTime QwtDate::ceil (const QDateTime & dateTime, IntervalType intervalType) [static]¶

Ceil a datetime according the interval type

Parameters:

Returns:

See also:

QDate QwtDate::dateOfWeek0 (int year, Week0Type type) [static]¶

Date of the first day of the first week for a year. The first day of a week depends on the current locale ( QLocale::firstDayOfWeek() ).

Parameters:

Returns:

See also:

QDateTime QwtDate::floor (const QDateTime & dateTime, IntervalType intervalType) [static]¶

Floor a datetime according the interval type

Parameters:

Returns:

See also:

QDate QwtDate::maxDate () [static]¶

Maximum for the supported date range

The range of valid dates depends on how QDate stores the Julian day internally.

• For Qt4 it is 'Tue Jun 3 5874898'
• For Qt5 it is 'Tue Dec 31 2147483647'

Returns:

See also:

Note:

QDate QwtDate::minDate () [static]¶

Minimum for the supported date range

The range of valid dates depends on how QDate stores the Julian day internally.

• For Qt4 it is 'Tue Jan 2 -4713'
• For Qt5 it is 'Thu Jan 1 -2147483648'

Returns:

See also:

QDateTime QwtDate::toDateTime (double value, Qt::TimeSpec timeSpec = Qt::UTC) [static]¶

Translate from double to QDateTime

Parameters:

Returns:

See also:

Note:

double QwtDate::toDouble (const QDateTime & dateTime) [static]¶

Translate from QDateTime to double

Parameters:

Returns:

See also:

Warning:

QString QwtDate::toString (const QDateTime & dateTime, const QString & format, Week0Type week0Type) [static]¶

Translate a datetime into a string

Beside the format expressions documented in QDateTime::toString() the following expressions are supported:

• w
  week number: ( 1 - 53 )
• ww
  week number with a leading zero ( 01 - 53 )

As week 1 usually starts in the previous year a special rule is applied for formats, where the year is expected to match the week number - even if the date belongs to the previous year.

Parameters:

Returns:

See also:

int QwtDate::utcOffset (const QDateTime & dateTime) [static]¶

Offset in seconds from Coordinated Universal Time

The offset depends on the time specification of dateTime:

• Qt::UTC 0, dateTime has no offset
• Qt::OffsetFromUTC returns dateTime.utcOffset()
• Qt::LocalTime: number of seconds from the UTC

For Qt::LocalTime the offset depends on the timezone and daylight savings.

Parameters:

Returns:

int QwtDate::weekNumber (const QDate & date, Week0Type type) [static]¶

Find the week number of a date

• QwtDate::FirstThursday
  Corresponding to ISO 8601 ( see QDate::weekNumber() ).
• QwtDate::FirstDay
  Number of weeks that have begun since dateOfWeek0().

Parameters:

Returns: