LocalDateTime Class Reference

#include <datetime.h>

Detailed Description

At some point developers have to deal with times, dates and timezones. This topic can promote headaches because it can be quite complex. In general you have to be aware of differences in timezones, especially when your software runs on mobile devices are you let the user share data across countries (or even within the same country).

In this header file you find some convenient helper functions and classes to reduce the amount of effort you have to put into to handle this topic to a minimum. The implementation and definition of the classes rely on the ISO 8601. Use the UniversalDateTime whenever possible to store normalized time and date values and convert them to a LocalDateTime instance as late as possible (e.g. for a local string output). An object representing a local 'time and date' of the current system time. All members are public and are allowed to be modified for custom needs. Keep in mind that you have to ensure that the values are correct and valid when converting an object back to UniversalDateTime, otherwise the behavior is undefined.

Public Member Functions
Bool	IsLeapYear () const
DAYOFWEEK	GetDayOfWeek () const
UniversalDateTime	ConvertToUniversalDateTime () const
Bool	operator== (const LocalDateTime &x) const
Bool	operator!= (const LocalDateTime &x) const
void	Reset ()
String	FormatTime (const Char *formatString) const
String	ToString (const FormatStatement *formatStatement=nullptr) const
HashInt	GetHashCode () const

Static Public Member Functions
static TimeValue	GetTimezoneOffset (Bool *daylightSavingTime=nullptr)
static Bool	IsLeapYear (Int year)
static DAYOFWEEK	GetDayOfWeek (Int lYear, Int lMonth, Int lDay)
static LocalDateTime	GetNow ()
static Result< LocalDateTime >	FromString (const String &dateTimeStr, const Char *formatString)
static Result< LocalDateTime >	FromValues (Int32 year, UChar month, UChar day, UChar hour, UChar minute, UChar second, DST daylightSavingTime=DST::AUTOMATIC)
static LocalDateTime	FromUnixTimestamp (UInt64 timestamp)

Public Attributes
Int32	_year
UChar	_month
UChar	_day
UChar	_hour
UChar	_minute
UChar	_second
DST	_daylightSavingTime

Member Function Documentation

IsLeapYear() [1/2]

Bool IsLeapYear

(

)

const

Check if the set year is a leap year.

Returns

True for a leap year, otherwise false.

GetDayOfWeek() [1/2]

DAYOFWEEK GetDayOfWeek

(

)

const

Return the day of the set time.

Returns

See DAYOFWEEK

ConvertToUniversalDateTime()

UniversalDateTime ConvertToUniversalDateTime

(

)

const

Converts the local time to the universal date-time

Returns

The normalized time.

operator==()

Bool operator==

(

const LocalDateTime &

x

)

const

Compare operator ==. The objects must represent a date and time in the same timezone. The Daylight Saving Time is not compared.

Returns

True if both UniversalDateTime are identical.

operator!=()

Bool operator!=

(

const LocalDateTime &

x

)

const

Reset()

void Reset

(

)

Resets the date-time object and sets all members to 0.

FormatTime()

String FormatTime

(

const Char *

formatString

)

const

Formats the time into a specific format defined be the format string.

Parameters

[in]

formatString

Optional. OS depending C lib format string (see strftime). "%Y-%m-%d %H:%M:%S" is used if formatString is nullptr.

Returns

Formated String of the date-time.

ToString()

String ToString

(

const FormatStatement *

formatStatement = nullptr

)

const

GetHashCode()

HashInt GetHashCode

(

)

const

Returns the hash value of this object. This value can be used for all HashSet<>/HashMap<> classes.

GetTimezoneOffset()

static TimeValue GetTimezoneOffset ( Bool *  daylightSavingTime = nullptr )

static

Return the current timezone offset to the universal time coordinate (UTC).

Parameters

[out]

daylightSavingTime

True if Daylight Saving Time effects the local time.

Returns

The timezone offset.

IsLeapYear() [2/2]

static Bool IsLeapYear ( Int  year )

static

Check if the passed year is a leap year.

Parameters

[in]

year

Year value.

Returns

True for a leap year, otherwise false.

GetDayOfWeek() [2/2]

static DAYOFWEEK GetDayOfWeek ( Int  lYear, Int  lMonth, Int  lDay  )

static

Return the day of the passed date.

Parameters

[in]	lYear	Year value.
[in]	lMonth	Month value.
[in]	lDay	Day value.

Returns

See DAYOFWEEK

GetNow()

static LocalDateTime GetNow ( )

static

Return the current date-time object of the current time zone.

Returns

See LocalDateTime

FromString()

static Result<LocalDateTime> FromString ( const String &  dateTimeStr, const Char *  formatString  )

static

Creates a date-time object by the passed string and its passed format string. An example:

iferr_scope;
LocalDateTime dt = LocalDateTime::FromString(str, "%a, %d %b %Y %H:%M:%S") iferr_return;

Parameters

[in]	dateTimeStr	The time string.
[in]	formatString	The matching format string.

Returns

The date-time object or an error if the passed date-time string cannot be resolved by the format string.

FromValues()

static Result<LocalDateTime> FromValues ( Int32  year, UChar  month, UChar  day, UChar  hour, UChar  minute, UChar  second, DST  daylightSavingTime = DST::AUTOMATIC  )

static

Creates a local date-time object by the passed date values.

Warning

The passed values are not checked for their validity!

Parameters

[in]	year	Year value [e.g. 2015]
[in]	month	Month value value [1-12]
[in]	day	Day value [1-31]
[in]	hour	Hour value [0-23]
[in]	minute	Minute value [0-59]
[in]	second	Second value [0-59]
[in]	daylightSavingTime	Optional Daylight Saving Time information. See DST.

Returns

date-time object.

FromUnixTimestamp()

static LocalDateTime FromUnixTimestamp ( UInt64  timestamp )

static

Create a local date-time object by passing a Unix time stamp.

Parameters

[in]

timestamp

The local Unix time stamp where 0 represents the 01/01/1970-00:00 in the current timezone.

Returns

The local date-time object.

Member Data Documentation

_year

Int32 _year

Full year, e.g. 2014.

_month

UChar _month

1..12

_day

UChar _day

1..31

_hour

UChar _hour

0..23

_minute

UChar _minute

0..59

_second

UChar _second

0..59

_daylightSavingTime

DST _daylightSavingTime