Date

The GDate data structure represents a day between January 1, Year 1, and sometime a few thousand years in the future (right now it will go to the year 65535 or so, but g_date_set_parse() only parses up to the year 8000 or so - just count on "a few thousand"). GDate is meant to represent everyday dates, not astronomical dates or historical dates or ISO timestamps or the like. It extrapolates the current Gregorian calendar forward and backward in time; there is no attempt to change the calendar to match time periods or locations. GDate does not store time information; it represents a day.

The GDate implementation has several nice features; it is only a 64-bit struct, so storing large numbers of dates is very efficient. It can keep both a Julian and day-month-year representation of the date, since some calculations are much easier with one representation or the other. A Julian representation is simply a count of days since some fixed day in the past; for GDate the fixed day is January 1, 1 AD. ("Julian" dates in the GDate API aren't really Julian dates in the technical sense; technically, Julian dates count from the start of the Julian period, Jan 1, 4713 BC).

GDate is simple to use. First you need a "blank" date; you can get a dynamically allocated date from g_date_new(), or you can declare an automatic variable or array and initialize it to a sane state by calling g_date_clear(). A cleared date is sane; it's safe to call g_date_set_dmy() and the other mutator functions to initialize the value of a cleared date. However, a cleared date is initially invalid, meaning that it doesn't represent a day that exists. It is undefined to call any of the date calculation routines on an invalid date. If you obtain a date from a user or other unpredictable source, you should check its validity with the g_date_valid() predicate. g_date_valid() is also used to check for errors with g_date_set_parse() and other functions that can fail. Dates can be invalidated by calling g_date_clear() again.

It is very important to use the API to access the GDate struct. Often only the day-month-year or only the Julian representation is valid. Sometimes neither is valid. Use the API.

GLib also features GDateTime which represents a precise time.

class Date {

GDate* gDate;

GDate* getDateStruct();

void* getStruct();

this(GDate* gDate);

this(GDateDay day, GDateMonth month, GDateYear year);

this(uint julianDay);

void clear(uint nDates);

void setDay(GDateDay day);

void setMonth(GDateMonth month);

void setYear(GDateYear year);

void setDmy(GDateDay day, GDateMonth month, GDateYear y);

void setJulian(uint julianDate);

void setTime(GTime time);

void setTimeT(uint timet);

void setTimeVal(GTimeVal timeval);

void setParse(string str);

void addDays(uint nDays);

void subtractDays(uint nDays);

void addMonths(uint nMonths);

void subtractMonths(uint nMonths);

void addYears(uint nYears);

void subtractYears(uint nYears);

int daysBetween(Date date2);

int compare(Date rhs);

void clamp(Date minDate, Date maxDate);

void order(Date date2);

GDateDay getDay();

GDateMonth getMonth();

GDateYear getYear();

uint getJulian();

GDateWeekday getWeekday();

uint getDayOfYear();

static ubyte getDaysInMonth(GDateMonth month, GDateYear year);

int isFirstOfMonth();

int isLastOfMonth();

static int isLeapYear(GDateYear year);

uint getMondayWeekOfYear();

static ubyte getMondayWeeksInYear(GDateYear year);

uint getSundayWeekOfYear();

static ubyte getSundayWeeksInYear(GDateYear year);

uint getIso8601_WeekOfYear();

static gsize strftime(char[] s, string format, Date date);

void toStructTm(void* tm);

static int validDay(GDateDay day);

static int validMonth(GDateMonth month);

static int validYear(GDateYear year);

static int validDmy(GDateDay day, GDateMonth month, GDateYear year);

static int validJulian(uint julianDate);

static int validWeekday(GDateWeekday weekday);

}

Constructors

this this(GDate* gDate): Sets our main struct and passes it to the parent class
this this(): Allocates a GDate and initializes it to a sane state. The new date will be cleared (as if you'd called g_date_clear()) but invalid (it won't represent an existing day). Free the return value with g_date_free().
this this(GDateDay day, GDateMonth month, GDateYear year): Like g_date_new(), but also sets the value of the date. Assuming the day-month-year triplet you pass in represents an existing day, the returned date will be valid.
this this(uint julianDay): Like g_date_new(), but also sets the value of the date. Assuming the Julian day number you pass in is valid (greater than 0, less than an unreasonably large number), the returned date will be valid.

Destructor

~this ~this(): Undocumented in source.

Members

Functions

addDays void addDays(uint nDays): Increments a date some number of days. To move forward by weeks, add weeks*7 days. The date must be valid.
addMonths void addMonths(uint nMonths): Increments a date by some number of months. If the day of the month is greater than 28, this routine may change the day of the month (because the destination month may not have the current day in it). The date must be valid.
addYears void addYears(uint nYears): Increments a date by some number of years. If the date is February 29, and the destination year is not a leap year, the date will be changed to February 28. The date must be valid.
clamp void clamp(Date minDate, Date maxDate): If date is prior to min_date, sets date equal to min_date. If date falls after max_date, sets date equal to max_date. Otherwise, date is unchanged. Either of min_date and max_date may be NULL. All non-NULL dates must be valid.
clear void clear(uint nDates): Initializes one or more GDate structs to a sane but invalid state. The cleared dates will not represent an existing date, but will not contain garbage. Useful to init a date declared on the stack. Validity can be tested with g_date_valid().
compare int compare(Date rhs): qsort()-style comparison function for dates. Both dates must be valid.
daysBetween int daysBetween(Date date2): Computes the number of days between two dates. If date2 is prior to date1, the returned value is negative. Both dates must be valid.
free void free(): Frees a GDate returned from g_date_new().
getDateStruct GDate* getDateStruct(): Undocumented in source. Be warned that the author may not have intended to support it.
getDay GDateDay getDay(): Returns the day of the month. The date must be valid.
getDayOfYear uint getDayOfYear(): Returns the day of the year, where Jan 1 is the first day of the year. The date must be valid.
getIso8601_WeekOfYear uint getIso8601_WeekOfYear(): Returns the week of the year, where weeks are interpreted according to ISO 8601. Since 2.6
getJulian uint getJulian(): Returns the Julian day or "serial number" of the GDate. The Julian day is simply the number of days since January 1, Year 1; i.e., January 1, Year 1 is Julian day 1; January 2, Year 1 is Julian day 2, etc. The date must be valid.
getMondayWeekOfYear uint getMondayWeekOfYear(): Returns the week of the year, where weeks are understood to start on Monday. If the date is before the first Monday of the year, return 0. The date must be valid.
getMonth GDateMonth getMonth(): Returns the month of the year. The date must be valid.
getStruct void* getStruct(): the main Gtk struct as a void*
getSundayWeekOfYear uint getSundayWeekOfYear(): Returns the week of the year during which this date falls, if weeks are understood to being on Sunday. The date must be valid. Can return 0 if the day is before the first Sunday of the year.
getWeekday GDateWeekday getWeekday(): Returns the day of the week for a GDate. The date must be valid.
getYear GDateYear getYear(): Returns the year of a GDate. The date must be valid.
isFirstOfMonth int isFirstOfMonth(): Returns TRUE if the date is on the first of a month. The date must be valid.
isLastOfMonth int isLastOfMonth(): Returns TRUE if the date is the last day of the month. The date must be valid.
order void order(Date date2): Checks if date1 is less than or equal to date2, and swap the values if this is not the case.
setDay void setDay(GDateDay day): Sets the day of the month for a GDate. If the resulting day-month-year triplet is invalid, the date will be invalid.
setDmy void setDmy(GDateDay day, GDateMonth month, GDateYear y): Sets the value of a GDate from a day, month, and year. The day-month-year triplet must be valid; if you aren't sure it is, call g_date_valid_dmy() to check before you set it.
setJulian void setJulian(uint julianDate): Sets the value of a GDate from a Julian day number.
setMonth void setMonth(GDateMonth month): Sets the month of the year for a GDate. If the resulting day-month-year triplet is invalid, the date will be invalid.
setParse void setParse(string str): Parses a user-inputted string str, and try to figure out what date it represents, taking the current locale into account. If the string is successfully parsed, the date will be valid after the call. Otherwise, it will be invalid. You should check using g_date_valid() to see whether the parsing succeeded. This function is not appropriate for file formats and the like; it isn't very precise, and its exact behavior varies with the locale. It's intended to be a heuristic routine that guesses what the user means by a given string (and it does work pretty well in that capacity).
setTime void setTime(GTime time): Warning g_date_set_time has been deprecated since version 2.10 and should not be used in newly-written code. Use g_date_set_time_t() instead. Sets the value of a date from a GTime value. The time to date conversion is done using the user's current timezone.
setTimeT void setTimeT(uint timet): Sets the value of a date to the date corresponding to a time specified as a time_t. The time to date conversion is done using the user's current timezone. Since 2.10
setTimeVal void setTimeVal(GTimeVal timeval): Sets the value of a date from a GTimeVal value. Note that the tv_usec member is ignored, because GDate can't make use of the additional precision. The time to date conversion is done using the user's current timezone. Since 2.10
setYear void setYear(GDateYear year): Sets the year for a GDate. If the resulting day-month-year triplet is invalid, the date will be invalid.
subtractDays void subtractDays(uint nDays): Moves a date some number of days into the past. To move by weeks, just move by weeks*7 days. The date must be valid.
subtractMonths void subtractMonths(uint nMonths): Moves a date some number of months into the past. If the current day of the month doesn't exist in the destination month, the day of the month may change. The date must be valid.
subtractYears void subtractYears(uint nYears): Moves a date some number of years into the past. If the current day doesn't exist in the destination year (i.e. it's February 29 and you move to a non-leap-year) then the day is changed to February 29. The date must be valid.
toStructTm void toStructTm(void* tm): Fills in the date-related bits of a struct tm using the date value. Initializes the non-date parts with something sane but meaningless.
valid int valid(): Returns TRUE if the GDate represents an existing day. The date must not contain garbage; it should have been initialized with g_date_clear() if it wasn't allocated by one of the g_date_new() variants.

Static functions

getDaysInMonth ubyte getDaysInMonth(GDateMonth month, GDateYear year): Returns the number of days in a month, taking leap years into account.
getMondayWeeksInYear ubyte getMondayWeeksInYear(GDateYear year): Returns the number of weeks in the year, where weeks are taken to start on Monday. Will be 52 or 53. The date must be valid. (Years always have 52 7-day periods, plus 1 or 2 extra days depending on whether it's a leap year. This function is basically telling you how many Mondays are in the year, i.e. there are 53 Mondays if one of the extra days happens to be a Monday.)
getSundayWeeksInYear ubyte getSundayWeeksInYear(GDateYear year): Returns the number of weeks in the year, where weeks are taken to start on Sunday. Will be 52 or 53. The date must be valid. (Years always have 52 7-day periods, plus 1 or 2 extra days depending on whether it's a leap year. This function is basically telling you how many Sundays are in the year, i.e. there are 53 Sundays if one of the extra days happens to be a Sunday.)
isLeapYear int isLeapYear(GDateYear year): Returns TRUE if the year is a leap year. [5]
strftime gsize strftime(char[] s, string format, Date date): Generates a printed representation of the date, in a locale-specific way. Works just like the platform's C library strftime() function, but only accepts date-related formats; time-related formats give undefined results. Date must be valid. Unlike strftime() (which uses the locale encoding), works on a UTF-8 format string and stores a UTF-8 result. This function does not provide any conversion specifiers in addition to those implemented by the platform's C library. For example, don't expect that using g_date_strftime() would make the %F provided by the C99 strftime() work on Windows where the C library only complies to C89.
validDay int validDay(GDateDay day): Returns TRUE if the day of the month is valid (a day is valid if it's between 1 and 31 inclusive).
validDmy int validDmy(GDateDay day, GDateMonth month, GDateYear year): Returns TRUE if the day-month-year triplet forms a valid, existing day in the range of days GDate understands (Year 1 or later, no more than a few thousand years in the future).
validJulian int validJulian(uint julianDate): Returns TRUE if the Julian day is valid. Anything greater than zero is basically a valid Julian, though there is a 32-bit limit.
validMonth int validMonth(GDateMonth month): Returns TRUE if the month value is valid. The 12 GDateMonth enumeration values are the only valid months.
validWeekday int validWeekday(GDateWeekday weekday): Returns TRUE if the weekday is valid. The seven GDateWeekday enumeration values are the only valid weekdays.
validYear int validYear(GDateYear year): Returns TRUE if the year is valid. Any year greater than 0 is valid, though there is a 16-bit limit to what GDate will understand.

Variables

gDate GDate* gDate;: the main Gtk struct

Meta

Source

See Implementation

glib Date classes

Date